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Ogasawara Yasushi

Faculty of Engineering　Applied Chemistry　BiotechnologyProfessor

Researcher basic information

■ Degree
  • 博士（理学）, 東京工業大学
■ URL
researchmap URLホームページURL■ Various IDs
Researcher number
  • 20732986
ORCID IDJ-Global ID■ Research Keywords and Fields
Research Keyword
  • Biosynthesis
  • Natural Product Chemistry
Research Field
  • Life Science, Bioorganic chemistry
■ Educational Organization

Career

■ Career
Career
  • Apr. 2026 - Present
    Hokkaido University, Faculty of Engineering, Professor, Japan
  • Jan. 2021 - Mar. 2026
    Hokkaido University, Faculty of Engineering, Associate Professor, Japan
  • Apr. 2014 - Dec. 2020
    Hokkaido University, Faculty of Engineering, 助教, Japan
  • Jan. 2013 - Mar. 2014
    The University of New Mexico, Department of Chemistry and Chemical Biology, Research Assistant Professor, United States
Committee Memberships
  • Apr. 2023 - Present
    Japan Society for Bioscience, Biotechnology, and Agrochemistry, -, Society

Research activity information

■ Awards
  • Jun. 2024, 天野エンザイム 科学技術振興財団, 第25回酵素応用シンポジウム 研究奨励賞
    ペプチドにD体アミノ酸を導入する新規異性化酵素の精密解析とその応用
    小笠原 泰志
  • Mar. 2021, Japan Society for Bioscience, Biotechnology, and Agrochemistry, Hot Topics Award
    Epimerase involved in polyglutamic acid biosynthesis
    Hinata KATO;Yasushi OGASAWARA;Tohru DAIRI
  • Mar. 2019, 日本農芸化学会, トピックス賞
    in vitro解析による多価不飽和脂肪酸生合成酵素の炭素鎖長制御機構の解明
    林祥平;小笠原泰志;佐藤康治;丸山千登勢;濱野吉十;氏原哲朗;大利徹
  • Mar. 2018, 日本農芸化学会, 奨励賞
    ペプチドの構造に多様性を与える新規酵素の探索
    小笠原 泰志
  • Mar. 2017, Japan Society for Bioscience, Biotechnology, and Agrochemistry, Hot Topics Award
    An unprecedented glutamate epimerase for bacterial peptidoglycan biosynthesis
    Ruoyin Feng;Yasuharu Satoh;Yasushi Ogasawara;Tohru Yoshimura;Tohru Dairi
■ Papers
  • tRNA-Dependent Chemoenzymatic Transformation of Aminoacyl Pendant Moieties of Streptothricin Antibiotics.
    Chitose Maruyama; Yu Nakashima; Kanki Matsuda; Sherif A Hamdy; Shun Uchiyama; Yuki Goto; Takahiro Mori; Yasushi Ogasawara; Kazuo Shin-Ya; Ikuro Abe; Tohru Dairi; Hiroaki Suga; Hiroyuki Morita; Yoshimitsu Hamano
    Journal of the American Chemical Society, 148, 11, 12154, 12165, 25 Mar. 2026, [International Magazine]
    English, Scientific journal, Streptothricin (ST) antibiotics are promising agents against multidrug-resistant pathogens and are structurally classified into two groups, containing either a β-lysyl or a glycyl pendant moiety attached via an amide bond to an amino sugar core. These pendant moieties are essential determinants of the biological activity and selective toxicity of ST antibiotics. We previously demonstrated that during ST biosynthesis, the β-lysyl pendant moiety is installed by nonribosomal peptide synthetases, whereas the glycyl pendant moiety is generated by a Gly-tRNAGly-dependent amide-forming enzyme. Here, we present a chemoenzymatic approach to transform aminoacyl pendant moieties using the promiscuous tRNA-dependent amide-forming enzyme Sba18. Remarkably, Sba18 generates two new ST derivatives, alanylthricin and serylthricin, by utilizing Ala-tRNAAla and Ser-tRNASer, respectively. Moreover, Sba18 accepts aminoacyl-tRNA mimics prepared by flexizyme-mediated charging of chemically synthesized aminoacyl groups and produces additional 11 ST derivatives. Alanylthricin and serylthricin retain antibiotic activity, demonstrating that this tRNA-dependent chemoenzymatic approach provides a viable strategy for expanding the structural diversity of streptothricin antibiotics. Furthermore, structural comparison of Sba18 with its Gly-tRNAGly-specific orthologue Sbb17 elucidates the catalytic and substrate-recognition mechanisms underlying the broad specificity of Sba18. These structural insights provide a foundation for expanding the structural diversity not only of ST antibiotics but also of other peptide natural products biosynthesized using aminoacyl-tRNAs.
  • Functional Analysis of Three Dehydratase Domains, DH PKS , DH1 FabA , and DH2 FabA , in Microalgal Docosahexaenoic Acid Synthase
    Tomoya Kawata; Hiyu Kobayashi; Makoto Otsuka; Chitose Maruyama; Yoshimitsu Hamano; Takeshi Tsunoda; Yasushi Ogasawara; Tohru Dairi
    ChemistryEurope, 4, 1, Wiley, 05 Jan. 2026, [Peer-reviewed], [Corresponding author]
    Scientific journal, Schizochytrium sp., a eukaryotic microalga, biosynthesizes docosahexaenoic acid (DHA; C22:6 ω 3) by DHA synthase, which is composed of three subunits (OrfA to C) possessing multiple catalytic domains. The enzyme has three dehydratase (DH) domains, DH PKS in OrfA and tandem DH FabA (DH1 FabA and DH2 FabA ) domains in OrfC. In this study, the function of each of the DH domains was investigated by in vivo heterologous expression experiments in Escherichia coli and in vitro studies with recombinant truncated OrfA containing DH PKS and full‐length OrfC, in which one of the tandem DH FabA domains was inactivated by site‐directed mutagenesis, and acyl–acyl carrier protein (ACP) intermediates. Following heterologous expression, the DH1 FabA ‐ or DH2 FabA ‐inactivated enzyme produced no DHA, revealing that both domains are essential, while the DH PKS ‐inactivated enzyme showed significantly reduced DHA productivity, confirming that DH PKS is required for full production of DHA. Moreover, in vitro experiments showed that the C4‐ACP substrate was accepted by all of the DHs, but DH PKS and DH2 FabA showed higher activities than DH1 FabA . DH1 FabA catalyzed two types of reactions: (de)hydrations of C10‐, C16‐, and C22‐ACP substrates and (de)hydrations/2‐ trans to 2‐ cis isomerization of C8‐, C14‐, and C20‐ACP substrates. By contrast, DH2 FabA catalyzed (de)hydrations/2‐ trans to 3‐ cis isomerization of C6‐, C12‐, and C18‐ACP substrates.
  • Identification of peptaibols as specific inhibitors of the futalosine pathway.
    Marie Kikuchi; Haruka Kiyanagi; Takeshi Tsunoda; Yuki Inahashi; Kenichi Nonaka; Tohru Dairi; Yasushi Ogasawara
    Bioscience, biotechnology, and biochemistry, 89, 7, 985, 989, 23 Jun. 2025, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
    English, Scientific journal, Menaquinone is an indispensable cofactor in the electron-transfer pathway for most Gram-positive bacteria. While most bacteria biosynthesize menaquinone by the well-known canonical pathway, some bacteria including Helicobacter pylori, which is a pathogen causing stomach cancer, use the futalosine pathway. Because beneficial intestinal bacteria such as lactobacilli use the canonical pathway, the futalosine pathway will be a great target for developing antibiotics specific to H. pylori. In this study, we searched for such metabolites from actinomycetes and fungi and identified 4 new peptaibols from culture broth of Verruciconidia sp. FKI-8918 as specific inhibitors of the futalosine pathway.
  • Substrate specificities of two ketosynthases in eukaryotic microalgal and prokaryotic marine bacterial DHA synthases
    Kaito Ogata; Riku Nakama; Hiyu Kobayashi; Tomoya Kawata; Chitose Maruyama; Takeshi Tsunoda; Tetsuro Ujihara; Yoshimitsu Hamano; Yasushi Ogasawara; Tohru Dairi
    Proceedings of the National Academy of Sciences, 25 Mar. 2025, [Peer-reviewed], [Corresponding author]
    Scientific journal
  • Comparison of a Nonheme Iron Cyclopropanase with a Homologous Hydroxylase Reveals Mechanistic Features Associated with Distinct Reaction Outcomes.
    Yu-Cong Zheng; Xiaojun Li; Lide Cha; Jared C Paris; Charalambos Michael; Richiro Ushimaru; Yasushi Ogasawara; Ikuro Abe; Yisong Guo; Wei-Chen Chang
    Journal of the American Chemical Society, 147, 7, 6162, 6170, 19 Feb. 2025, [Peer-reviewed], [Corresponding author], [International Magazine]
    English, Scientific journal, Despite the diversity of reactions catalyzed by mononuclear iron and 2-oxoglutarate-dependent enzymes, the factors that lead to diverse reaction outcomes beyond canonical hydroxylation remain elusive. Cyclopropanation reactions are of particular interest not only due to the prevalence of cyclopropane moieties in pharmaceuticals but also due to the chemistry that allows cyclopropanation to outcompete oxygen rebound. HrmJ is one such cyclopropanase from the biosynthetic pathway of hormaomycin; however, a homologue is herein discovered that instead catalyzes C-hydroxylation of the same nitro enolate substrate. These enzymes were reconstituted with Mn(II) and V(IV)═O as mimics of the resting (Fe(II)) and reactive (Fe(IV)═O) intermediate states, respectively. Corresponding crystal structures of the cyclopropanase bound with a substrate imply H atom transfer via an offline π-pathway. In contrast, analogous structural analysis of the hydroxylase implies H atom abstraction likely proceeds through a σ-pathway. Preparation of isotopically labeled substrates and stopped-flow kinetic analyses indicate that while the pro-S hydrogen of C4 is abstracted in both enzymes, the Fe(IV)═O intermediate reacts ca. 17-fold faster in the active site of the hydroxylase, consistent with the mechanistic assignments. These results also support a correlation between the mechanism of H atom transfer and the subsequent fate of the substrate radical once generated. A subtle difference in substrate positioning not only affects the H atom abstraction pathway but also allows the nitro enolate moiety to intercept the resulting substrate radical in the active site of the cyclopropase, thereby facilitating intramolecular C-C bond formation in a stereoselective manner.
  • Biosynthesis of lactacystin as a proteasome inhibitor.
    Takeshi Tsunoda; Shunkichi Furumura; Haruka Yamazaki; Chitose Maruyama; Yoshimitsu Hamano; Yasushi Ogasawara; Tohru Dairi
    Communications chemistry, 8, 1, 9, 9, 13 Jan. 2025, [Peer-reviewed], [Corresponding author], [International Magazine]
    English, Scientific journal, Lactacystin is an irreversible proteasome inhibitor isolated from Streptomyces lactacystinicus. Despite its importance for its biological activity, the biosynthesis of lactacystin remains unknown. In this study, we identified the lactacystin biosynthetic gene cluster by gene disruption and heterologous expression experiments. We also examined the functions of the genes encoding a PKS/NRPS hybrid protein (LctA), NRPS (LctB), ketosynthase-like cyclase (LctC), cytochrome P450 (LctD), MbtH-like protein (LctE), and formyltransferase (LctF) by in vivo and in vitro experiments. In particular, we demonstrated that LctF directly transferred the formyl group of 10-N-formyl tetrahydrofolate to CoA. The formyl group of formyl-CoA was then transferred to ACP1 by LctA_AT1 to form formyl-ACP1. This is the first example of an AT domain recognizing a formyl group. The formyl group is perhaps transferred to methylmalonate tethered on LctA_ACP2 to yield methylmalonyl-semialdehyde-ACP2. Then, it would be condensed with leucine bound to PCP in LctB by the C domain in LctA. Using a mimic compound, we confirmed that LctC catalyzed the formation of the cyclic α,α-disubstituted amino acid structure with concomitant release of the product from PCP. Thus, we figured out the overall biosynthesis of lactacystin including a novel role of a formyl group in a secondary metabolite.
  • Optimization of tyrosol-producing pathway with tyrosine decarboxylase and tyramine oxidase in high-tyrosine-producing Escherichia coli
    Ning Shen; Yasuharu Satoh; Daisuke Koma; Hiroyuki Ohashi; Yasushi Ogasawara; Tohru Dairi
    Journal of Bioscience and Bioengineering, 137, 2, 115, 123, Elsevier BV, Feb. 2024, [Peer-reviewed]
    Scientific journal
  • Identification of a new oligomycin derivative as a specific inhibitor of the alternative peptidoglycan biosynthetic pathway.
    Shuhei Umetsu; Takeshi Tsunoda; Haruka Kiyanagi; Yuki Inahashi; Kenichi Nonaka; Tohru Dairi; Yasushi Ogasawara
    The Journal of antibiotics, 10 Jan. 2024, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
    English, Scientific journal, Peptidoglycan is an important macromolecule in bacterial cell walls to maintain cell integrity, and its biosynthetic pathway has been well studied. Recently, we demonstrated that some bacteria such as Xanthomonas oryzae, a pathogen causing bacterial blight of rice, used an alternative pathway for peptidoglycan biosynthesis. In this pathway, MurD2, a MurD homolog, catalyzed the attachment of L-Glu to UDP-MurNAc-L-Ala and MurL, which did not show homology to any known protein, catalyzed epimerization of the terminal L-Glu of the MurD2 product to generate UDP-MurNAc-L-Ala-D-Glu. Because the alternative pathway also operates in some other plant pathogens and opportunistic pathogens, specific inhibitors of the alternative pathway could function as pesticides and antibiotics for these pathogens. In this study, we searched for specific inhibitors of the alternative pathway from metabolites produced by actinomycetes and identified a new oligomycin-class polyketide, which was revealed to inhibit the MurD2 reaction, in culture broth of Micromonospora sp. K18-0097.
  • Peptide Epimerase Responsible for d-Amino Acid Introduction in Poly-γ-glutamic Acid Biosynthesis
    Hinata Kato; Moeka Sakuta; Takeshi Tsunoda; Yu Nakashima; Hiroyuki Morita; Yasushi Ogasawara; Tohru Dairi
    Biomacromolecules, 25, 1, 349, 354, American Chemical Society (ACS), 14 Dec. 2023, [Peer-reviewed], [Corresponding author]
    Scientific journal
  • Peptide epimerase-dehydratase complex responsible for biosynthesis of the linaridin class ribosomal peptides.
    Wanlu Xiao; Takeshi Tsunoda; Chitose Maruyama; Yoshimitsu Hamano; Yasushi Ogasawara; Tohru Dairi
    Bioscience, biotechnology, and biochemistry, 87, 11, 1316, 1322, 04 Aug. 2023, [Peer-reviewed], [Corresponding author], [International Magazine]
    English, Scientific journal, Grisemycin, salinipeptin, and cypemycin belong to the linaridin class of ribosomally synthesized and posttranslationally modified peptides that contain multiple dehydrobutyrine and D-amino acid residues. The biosynthetic gene clusters of these linaridins lack obvious candidate genes for the dehydratase and epimerase required to introduce dehydrobutyrine and D-amino acid residues, respectively. However, we previously demonstrated that the grisemycin (grm) cluster contained cryptic dehydratase and epimerase genes by heterologous expression of this biosynthetic gene cluster in Streptomyces lividans and proposed that two genes (grmH and grmL) with unknown functions catalyze dehydration and epimerization reactions. In this study, we confirmed that both GrmH and GrmL, which were shown to constitute a protein complex by a co-purification experiment, were required to catalyze the dehydration, epimerization, and proteolytic cleavage of a precursor peptide GrmA by in vivo experiments. Furthermore, we demonstrated that GrmH/GrmL complex accepted salinipeptin and cypemycin precursor peptides, which possess three additional amino acids.
  • N-Formimidoylation/-iminoacetylation modification in aminoglycosides requires FAD-dependent and ligand-protein NOS bridge dual chemistry.
    Yung-Lin Wang; Chin-Yuan Chang; Ning-Shian Hsu; I-Wen Lo; Kuan-Hung Lin; Chun-Liang Chen; Chi-Fon Chang; Zhe-Chong Wang; Yasushi Ogasawara; Tohru Dairi; Chitose Maruyama; Yoshimitsu Hamano; Tsung-Lin Li
    Nature communications, 14, 1, 2528, 2528, 03 May 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Oxidized cysteine residues are highly reactive and can form functional covalent conjugates, of which the allosteric redox switch formed by the lysine-cysteine NOS bridge is an example. Here, we report a noncanonical FAD-dependent enzyme Orf1 that adds a glycine-derived N-formimidoyl group to glycinothricin to form the antibiotic BD-12. X-ray crystallography was used to investigate this complex enzymatic process, which showed Orf1 has two substrate-binding sites that sit 13.5 Å apart unlike canonical FAD-dependent oxidoreductases. One site could accommodate glycine and the other glycinothricin or glycylthricin. Moreover, an intermediate-enzyme adduct with a NOS-covalent linkage was observed in the later site, where it acts as a two-scissile-bond linkage facilitating nucleophilic addition and cofactor-free decarboxylation. The chain length of nucleophilic acceptors vies with bond cleavage sites at either N-O or O-S accounting for N-formimidoylation or N-iminoacetylation. The resultant product is no longer sensitive to aminoglycoside-modifying enzymes, a strategy that antibiotic-producing species employ to counter drug resistance in competing species.
  • Structure of lasso peptide epimerase MslH reveals metal-dependent acid/base catalytic mechanism
    Yu Nakashima; Atsushi Kawakami; Yasushi Ogasawara; Masatoshi Maeki; Manabu Tokeshi; Tohru Dairi; Hiroyuki Morita
    12 Jan. 2023, [Peer-reviewed]
  • First direct evidence for direct cell-membrane penetrations of polycationic homopoly(amino acid)s produced by bacteria
    Yamato Takeuchi; Kazunori Ushimaru; Kohei Kaneda; Chitose Maruyama; Takashi Ito; Kazuya Yamanaka; Yasushi Ogasawara; Hajime Katano; Yasuo Kato; Tohru Dairi; Yoshimitsu Hamano
    Communications Biology, 5, 1, Springer Science and Business Media LLC, 26 Oct. 2022, [Peer-reviewed]
    Scientific journal, Abstract

    Bacteria produce polycationic homopoly(amino acid)s, which are characterized by isopeptide backbones. Although the biological significance of polycationic homopoly(amino acid)s remains unclear, increasing attention has recently been focused on their potential use to achieve cellular internalization. Here, for the first time, we provide direct evidence that two representative bacterial polycationic isopeptides, ε-poly-l-α-lysine (ε-PαL) and ε-oligo-l-β-lysine (ε-OβL), were internalized into mammalian cells by direct cell-membrane penetration and then diffused throughout the cytosol. In this study, we used clickable ε-PαL and ε-OβL derivatives carrying a C-terminal azide group, which were enzymatically produced and then conjugated with a fluorescent dye to analyze subcellular localization. Interestingly, fluorescent proteins conjugated with the clickable ε-PαL or ε-OβL were also internalized into cells and diffused throughout the cytosol. Notably, a Cre recombinase conjugate with ε-PαL entered cells and mediated the Cre/loxP recombination, and ε-PαL was found to deliver a full-length IgG antibody to the cytosol and nucleus.
  • Biosynthetic Gene Cluster of Linaridin Peptides Contains Epimerase Gene
    Wanlu Xiao; Yasuharu Satoh; Yasushi Ogasawara; Tohru Dairi
    ChemBioChem, 23, 12, Wiley, 20 Jun. 2022, [Peer-reviewed], [Corresponding author]
    Scientific journal
  • Identification of Cyclopropane Formation in the Biosyntheses of Hormaomycins and Belactosins: Sequential Nitration and Cyclopropanation by Metalloenzymes
    Xiaojun Li; Ryo Shimaya; Tohru Dairi; Wei‐chen Chang; Yasushi Ogasawara
    Angewandte Chemie International Edition, 61, 7, Wiley, 27 Dec. 2021, [Peer-reviewed], [Last author, Corresponding author]
    Scientific journal
  • Identification of pulvomycin as an inhibitor of the futalosine pathway
    Yasushi Ogasawara; Shuhei Umetsu; Yuki Inahashi; Kenichi Nonaka; Tohru Dairi
    The Journal of Antibiotics, 20 Aug. 2021, [Peer-reviewed]
    English, Scientific journal
  • Discovery of an alternative pathway of peptidoglycan biosynthesis: A new target for pathway specific inhibitors
    Yasushi Ogasawara; Tohru Dairi
    Journal of Industrial Microbiology and Biotechnology, Oxford University Press ({OUP}), 11 Jun. 2021, [Peer-reviewed], [Corresponding author]
    Scientific journal, Abstract
    Peptidoglycan in bacterial cell walls is a biopolymer consisting of sugars and amino acids and plays important role in maintaining cell integrity from the environment. Its biosynthesis is a major target for antibiotics and the genes and enzymes involved in the biosynthetic pathway have been well studied. However, we recently identified an alternative pathway in the early stage of peptidoglycan biosynthesis in Xanthomonas oryzae, a plant pathogen causing bacterial blight disease of rice. The distribution of the alternative pathway is limited to relatively few bacterial genera that contain many pathogenic species, including Xylella and Stenotrophomonas, besides Xanthomonas. Thus, the alternative pathway is an attractive target for the development of narrow-spectrum antibiotics specific to pathogens. In this minireview, we summarize the discovery of the alternative pathway and identification of its specific inhibitors.
  • Identification of the peptide epimerase MslH responsible for d-amino acid introduction at the C-terminus of ribosomal peptides
    Zhi Feng; Yasushi Ogasawara; Tohru Dairi
    Chemical Science, 12, 7, 2567, 2574, Royal Society of Chemistry ({RSC}), 2021, [Peer-reviewed]
    Scientific journal,

    The biosynthesis of d-tryptophan containing lasso peptide MS-271 involves the epimerization of a ribosomal peptide MslA catalyzed by a novel class of metal- and cofactor-independent peptide epimerase MslH.

  • Recent advances in functional analysis of polyunsaturated fatty acid synthases
    Shohei Hayashi; Yasuharu Satoh; Yasushi Ogasawara; Tohru Dairi
    Current Opinion in Chemical Biology, 59, 30, 36, Elsevier {BV}, Dec. 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid are essential fatty acids for humans. PUFAs are biosynthesized by either desaturases/elongases from oleic acid or PUFA synthases from acetyl units. PUFA synthases are composed of three or four subunits, and each creates a specific PUFA even though the multiple catalytic domains in each subunit are very similar. We recently dissected these PUFA synthases by in vivo and in vitro experiments and elucidated how the enzymes control PUFA profiles. Moreover, for the first time, we converted a practical microalgal docosahexaenoic acid synthase into an eicosapentaenoic acid synthase based on the results.
  • High Production of Ergothioneine in Escherichia coli using the Sulfoxide Synthase from Methylobacterium strains
    Tomoyuki Kamide; Shun Takusagawa; Naoyuki Tanaka; Yasushi Ogasawara; Yusuke Kawano; Iwao Ohtsu; Yasuharu Satoh; Tohru Dairi
    Journal of Agricultural and Food Chemistry, 68, 23, 6390, 6394, American Chemical Society ({ACS}), 10 Jun. 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, We previously constructed a heterologous production system for ergothioneine (ERG) in Escherichia coli using five ERG biosynthesis genes (egtABCDE) from Mycobacterium smegmatis. However, significant amounts of hercynine (HER), an intermediate of ERG, as ERG were accumulated, suggesting that the reaction of EgtB catalyzing the attachment of γ-glutamylcysteine (γGC) to HER to yield hercynyl-γ-glutamylcysteine sulfoxide was a bottleneck. In this study, we searched for other EgtBs and found many egtB orthologs in diverse microorganisms. Among these, Methylobacterium strains possessed EgtBs that catalyze the direct conversion of HER into hercynylcysteine sulfoxide with l-cysteine (l-Cys) as a sulfur donor, in a manner similar to those of acidobacterial CthEgtB and fungal Egt1. An in vitro study with recombinant EgtBs from Methylobacterium brachiatum and Methylobacterium pseudosasicola clearly showed that both enzymes accepted l-Cys but not γGC. We reconstituted the ERG production system in E. coli with egtB from M. pseudosasicola; ERG productivity reached 657 mg L-1.
  • Characterization of the coformycin biosynthetic gene cluster in Streptomyces kaniharaensis.
    Daan Ren; Mark W Ruszczycky; Yeonjin Ko; Shao-An Wang; Yasushi Ogasawara; Minje Kim; Hung-Wen Liu
    Proceedings of the National Academy of Sciences of the United States of America, 117, 19, 10265, 10270, 12 May 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Coformycin and pentostatin are structurally related N-nucleoside inhibitors of adenosine deaminase characterized by an unusual 1,3-diazepine nucleobase. Herein, the cof gene cluster responsible for coformycin biosynthesis is identified. Reconstitution of the coformycin biosynthetic pathway in vitro demonstrates that it overlaps significantly with the early stages of l-histidine biosynthesis. Committed entry into the coformycin pathway takes place via conversion of a shared branch point intermediate to 8-ketocoformycin-[Formula: see text]-monophosphate catalyzed by CofB, which is a homolog of succinylaminoimidazolecarboxamide ribotide (SAICAR) synthetase. This reaction appears to proceed via a Dieckmann cyclization and a retro-aldol elimination, releasing ammonia and D-erythronate-4-phosphate as coproducts. Completion of coformycin biosynthesis involves reduction and dephosphorylation of the CofB product, with the former reaction being catalyzed by the NADPH-dependent dehydrogenase CofA. CofB also shows activation by adenosine triphosphate (ATP) despite the reaction requiring neither a phosphorylated nor an adenylated intermediate. This may serve to help regulate metabolic partitioning between the l-histidine and coformycin pathways.
  • Off-Loading Mechanism of Products in Polyunsaturated Fatty Acid Synthases.
    Shohei Hayashi; Yasushi Ogasawara; Yasuharu Satoh; Chitose Maruyama; Yoshimitsu Hamano; Tohru Dairi
    ACS chemical biology, 15, 3, 651, 656, American Chemical Society ({ACS}), 20 Mar. 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Marine microorganisms de novo biosynthesize polyunsaturated fatty acids such as docosahexaenoic acid and eicosapentaenoic acid by polyunsaturated fatty acid (PUFA) synthases composed of three or four polypeptides in a manner similar to fatty acid synthases (FASs). FASs usually possess thioesterase (TE) domains to release free fatty acids from acyl carrier protein (ACP)-tethered intermediates. Here, we investigated the off-loading mechanism with microalgal and bacterial PUFA synthases through in vivo and in vitro experiments. The in vitro experiments with acyltransferase (AT)-like domains and acyl-ACP substrates clearly demonstrated that the AT-like domains catalyzed the hydrolysis of acyl-ACPs to yield free fatty acids.
  • Subtle Control of Carbon Chain Length in Polyunsaturated Fatty Acid Synthases
    Mai Naka; Kenshin Ikeuchi; Shohei Hayashi; Yasuharu Satoh; Yasushi Ogasawara; Tohru Dairi
    ACS Chemical Biology, American Chemical Society ({ACS}), Nov. 2019, [Peer-reviewed]
  • Identification of actinomycin D as a specific inhibitor of the alternative pathway of peptidoglycan biosynthesis
    Yasushi Ogasawara; Yohei Shimizu; Yohei Sato; Tomoki Yoneda; Yasuhide Inokuma; Tohru Dairi
    The Journal of Antibiotics, 73, 2, 125, 127, Oct. 2019, [Peer-reviewed]
    English, Scientific journal
  • The Amipurimycin and Miharamycin Biosynthetic Gene Clusters: Unraveling the Origins of 2-Aminopurinyl Peptidyl Nucleoside Antibiotics
    Anthony J. Romo; Taro Shiraishi; Hideo Ikeuchi; Geng-Min Lin; Yujie Geng; Yu-Hsuan Lee; Priscilla H. Liem; Tianlu Ma; Yasushi Ogasawara; Kazuo Shin-ya; Makoto Nishiyama; Tomohisa Kuzuyama; Hung-wen Liu
    Journal of the American Chemical Society, 141, 36, 14152, 14159, American Chemical Society ({ACS}), Sep. 2019, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Peptidyl nucleoside antibiotics (PNAs) are a diverse class of natural products with promising biomedical activities. These compounds have tripartite structures composed of a core saccharide, a nucleobase, and one or more amino acids. In particular, amipurimycin and the miharamycins are novel 2-aminopurinyl PNAs with complex nine-carbon core saccharides and include the unusual amino acids (-)-cispentacin and N5-hydroxyarginine, respectively. Despite their interesting structures and properties, these PNAs have heretofore eluded biochemical scrutiny. Herein is reported the discovery and initial characterization of the miharamycin gene cluster in Streptomyces miharaensis (mhr) and the amipurimycin gene cluster (amc) in Streptomyces novoguineensis and Streptomyces sp. SN-C1. The gene clusters were identified using a comparative genomics approach, and heterologous expression of the amc cluster as well as gene interruption experiments in the mhr cluster support their role in the biosynthesis of amipurimycin and the miharamycins, respectively. The mhr and amc biosynthetic gene clusters characterized encode enzymes typical of polyketide biosynthesis instead of enzymes commonly associated with PNA biosynthesis, which, along with labeled precursor feeding studies, implies that the core saccharides found in the miharamycins and amipurimycin are partially assembled as polyketides rather than derived solely from carbohydrates. Furthermore, in vitro analysis of Mhr20 and Amc18 established their roles as ATP-grasp ligases involved in the attachment of the pendant amino acids found in these PNAs, and Mhr24 was found to be an unusual hydroxylase involved in the biosynthesis of N5-hydroxyarginine. Finally, analysis of the amc cluster and feeding studies also led to the proposal of a biosynthetic pathway for (-)-cispentacin.
  • Identification of the C-Glycoside Synthases during Biosynthesis of the Pyrazole-C-Nucleosides Formycin and Pyrazofurin.
    Angewandte Chemie (International ed. in English), Sep. 2019, [Peer-reviewed]
    C-Nucleosides are characterized by a C-C rather than a C-N linkage between the heterocyclic base and the ribofuranose ring. While the biosynthesis of pseudouridine-C-nucleosides has been studied, less is known about the pyrazole-C-nucleosides such as the formycins and pyrazofurin. Herein, genome screening of Streptomyces candidus NRRL 3601 led to the discovery of the pyrazofurin biosynthetic gene cluster pyf. In vitro characterization of gene product PyfQ demonstrated that it is able to catalyze formation of the C-glycoside carboxylhydroxylpyrazole ribonucleotide (CHPR) from 4-hydroxyl-1H-pyrazole-3,5-dicarboxylic acid and phosphoribosyl pyrophosphate (PRPP). Similarly, ForT, the PyfQ homologue in the formycin pathway, can catalyze the coupling of 4-amino-1H-pyrazole-3,5-dicarboxylic acid and PRPP to form carboxylaminopyrazole ribonucleotide. Finally, PyfP and PyfT are shown to catalyze amidation of CHPR to pyrazofurin 5'-phosphate thereby establishing the latter stages of both pyrazofurin and formycin biosynthesis.
  • In vitro characterization of MitE and MitB: Formation of N-acetylglucosaminyl-3-amino-5-hydroxybenzoyl-MmcB as a key intermediate in the biosynthesis of antitumor antibiotic mitomycins
    Yasushi Ogasawara; Yo Nakagawa; Chitose Maruyama; Yoshimitsu Hamano; Tohru Dairi
    Bioorganic & Medicinal Chemistry Letters, 29, 16, 2076, Elsevier {BV}, Aug. 2019, [Peer-reviewed]
  • Involvement of Peptide Epimerization in Poly-γ-glutamic Acid Biosynthesis
    Yasushi Ogasawara; Mayuko Shigematsu; Shota Sato; Hinata Kato; Tohru Dairi
    Organic Letters, American Chemical Society ({ACS}), Jun. 2019, [Peer-reviewed], [Lead author, Corresponding author]
  • Amino Acid Residues Recognizing Isomeric Glutamate Substrates in UDP-N-acetylmuramic acid-l-alanine-glutamate Synthetases
    Ruoyin Feng; Yasuharu Satoh; Hiroyuki Morita; Yasushi Ogasawara; Tohru Dairi
    ACS Chemical Biology, American Chemical Society ({ACS}), May 2019, [Peer-reviewed]
  • Control Mechanism for Carbon‐Chain Length in Polyunsaturated Fatty‐Acid Synthases
    Shohei Hayashi; Mai Naka; Kenshin Ikeuchi; Makoto Ohtsuka; Kota Kobayashi; Yasuharu Satoh; Yasushi Ogasawara; Chitose Maruyama; Yoshimitsu Hamano; Tetsuro Ujihara; Tohru Dairi
    Angewandte Chemie, Wiley, Apr. 2019, [Peer-reviewed]
  • Control Mechanism for Carbon-Chain Length in Polyunsaturated Fatty-Acid Synthases
    Tohru Dairi; Shohei Hayashi; Mai Naka; Kenshin Ikeuchi; Makoto Ohtsuka; Kota Kobayashi; Yasuharu Satoh; Yasushi Ogasawara; Chitose Maruyama; Yoshimitsu Hamano; Tetsuro Ujihara
    Angewandte Chemie International Edition, 58, 20, 6605, Wiley, Apr. 2019, [Peer-reviewed]
  • Identification of the Formycin A Biosynthetic Gene Cluster from Streptomyces kaniharaensis Illustrates the Interplay between Biological Pyrazolopyrimidine Formation and de Novo Purine Biosynthesis
    Shao-An Wang; Yeonjin Ko; Jia Zeng; Yujie Geng; Daan Ren; Yasushi Ogasawara; Seema Irani; Yan Jessie Zhang; Hung-wen Liu
    Journal of the American Chemical Society, American Chemical Society ({ACS}), Apr. 2019, [Peer-reviewed]
  • Control mechanism for cis double bond formation by polyunsaturated fatty acid synthases.
    Hayashi S; Satoh Y; Ogasawara Y; Maruyama C; Hamano Y; Ujihara T; Dairi T
    Angewandte Chemie (International ed. in English), Jan. 2019, [Peer-reviewed]
  • New enzymes for peptide biosynthesis in microorganisms
    Yasushi Ogasawara
    Bioscience, Biotechnology, and Biochemistry, 1, Informa {UK} Limited, Dec. 2018, [Peer-reviewed]
  • Searching for potent and specific antibiotics against pathogenic Helicobacter and Campylobacter strains.
    Ogasawara Y; Dairi T
    Journal of industrial microbiology & biotechnology, Nov. 2018, [Peer-reviewed]
  • Front Cover: Biosynthetic Gene Cluster of a d -Tryptophan-Containing Lasso Peptide, MS-271 (ChemBioChem 19/2018)
    Zhi Feng; Yasushi Ogasawara; Satoshi Nomura; Tohru Dairi
    ChemBioChem, 19, 19, 1998, Wiley, Oct. 2018, [Peer-reviewed]
  • Total Biosynthesis of Brassicicenes: Identification of a Key Enzyme for Skeletal Diversification.
    Tazawa A; Ye Y; Ozaki T; Liu C; Ogasawara Y; Dairi T; Higuchi Y; Kato N; Gomi K; Minami A; Oikawa H
    Organic letters, Sep. 2018, [Peer-reviewed]
  • Aplasmomycin and boromycin are specific inhibitors of the futalosine pathway.
    Shimizu Y; Ogasawara Y; Matsumoto A; Dairi T
    The Journal of antibiotics, 71, 11, 968, Springer Nature, Aug. 2018, [Peer-reviewed]
  • Biosynthetic Gene Cluster of a d-Tryptophan-Containing Lasso Peptide, MS-271.
    Feng Z; Ogasawara Y; Nomura S; Dairi T
    Chembiochem : a European journal of chemical biology, 19, 19, 2045, Wiley, Jul. 2018, [Peer-reviewed]
  • Enzymatic Formation of a Skipped Methyl-Substituted Octaprenyl Side Chain of Longestin (KS-505a): Involvement of Homo-IPP as a Common Extender Unit
    Taro Ozaki; Sandip S. Shinde; Lei Gao; Ryo Okuizumi; Chengwei Liu; Yasushi Ogasawara; Xiaoguang Lei; Tohru Dairi; Atsushi Minami; Hideaki Oikawa
    Angewandte Chemie - International Edition, 57, 22, 6629, 6632, Wiley-VCH Verlag, 28 May 2018, [Peer-reviewed]
    English, Scientific journal
  • Peptide epimerization machineries found in microorganisms
    Yasushi Ogasawara; Tohru Dairi
    Frontiers in Microbiology, 9, Frontiers Media S.A., 06 Feb. 2018, [Peer-reviewed]
    English
  • Functional analysis of methyltransferases participating in streptothricin-related antibiotic biosynthesis
    Haruka Niikura; Chitose Maruyama; Yasushi Ogasawara; Kazuo Shin-ya; Tohru Dairi; Yoshimitsu Hamano
    Journal of Bioscience and Bioengineering, 125, 2, 148, 154, Elsevier B.V., 01 Feb. 2018, [Peer-reviewed]
    English, Scientific journal
  • Synthesis of Acylborons by Ozonolysis of Alkenylboronates: Preparation of an Enantioenriched Amino Acid Acylboronate
    Jumpei Taguchi; Toshiki Ikeda; Rina Takahashi; Ikuo Sasaki; Yasushi Ogasawara; Tohru Dairi; Naoya Kato; Yasunori Yamamoto; Jeffrey W. Bode; Hajime Ito
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 56, 44, 13847, 13851, Oct. 2017, [Peer-reviewed]
    English, Scientific journal
  • BD-12生合成におけるN-formimidoyl基転移酵素の酵素学的諸性質
    新倉 春香; 丸山 千登勢; 小笠原 泰志; 大利 徹; 加藤 康夫; 濱野 吉十
    日本放線菌学会大会講演要旨集, 32回, 121, 121, 日本放線菌学会, Sep. 2017
    Japanese
  • Biosynthesis of Oligopeptides Using ATP-Grasp Enzymes
    Yasushi Ogasawara; Tohru Dairi
    CHEMISTRY-A EUROPEAN JOURNAL, 23, 45, 10714, 10724, Aug. 2017, [Peer-reviewed]
    English
  • BD-12生合成におけるN-formimidoyl基転移酵素の酵素学的諸性質
    新倉 春香; 丸山 千登勢; 小笠原 泰志; 大利 徹; 濱野 吉十
    日本生物工学会大会講演要旨集, 平成29年度, 258, 258, (公社)日本生物工学会, Aug. 2017
    Japanese
  • Frontispiece: Biosynthesis of Oligopeptides Using ATP-Grasp Enzymes
    Yasushi Ogasawara; Tohru Dairi
    Chemistry - A European Journal, 23, 45, Wiley, Aug. 2017, [Peer-reviewed]
  • N-Phenylacetylation and Nonribosomal Peptide Synthetases with Substrate Promiscuity for Biosynthesis of Heptapeptide Variants, JBIR-78 and JBIR-95
    Kunpei Takeda; Kohei Kemmoku; Yasuharu Satoh; Yasushi Ogasawara; Kazuo Shin-ya; Tohru Dairi
    ACS CHEMICAL BIOLOGY, 12, 7, 1813, 1819, Jul. 2017, [Peer-reviewed]
    English, Scientific journal
  • Identification of tirandamycins as specific inhibitors of the futalosine pathway
    Yasushi Ogasawara; Kensuke Kondo; Ayumi Ikeda; Rikako Harada; Tohru Dairi
    JOURNAL OF ANTIBIOTICS, 70, 6, 798, 800, Jun. 2017, [Peer-reviewed]
    English, Scientific journal
  • Identification and Characterization of Enzymes Catalyzing Pyrazolopyrimidine Formation in the Biosynthesis of Formycin A
    Yeonjin Ko; Shoo-An Wang; Yasushi Ogasawara; Mark W. Ruszczycky; Hung-Wen Liu
    ORGANIC LETTERS, 19, 6, 1426, 1429, Mar. 2017, [Peer-reviewed]
    English, Scientific journal
  • A Glycopeptidyl-Glutamate Epimerase for Bacterial Peptidoglycan Biosynthesis
    Ruoyin Feng; Yasuharu Satoh; Yasushi Ogasawara; Tohru Yoshimura; Tohru Dairi
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 139, 12, 4243, 4245, Mar. 2017, [Peer-reviewed]
    English, Scientific journal
  • Biosynthesis of the Carbonylmethylene Structure Found in the Ketomemicin Class of Pseudotripeptides
    Junpei Kawata; Taiki Naoe; Yasushi Ogasawara; Tohru Dairi
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 56, 8, 2026, 2029, Feb. 2017, [Peer-reviewed]
    English, Scientific journal
  • Characterization of three amidinotransferases involved in the biosynthesis of ketomemicins
    Yasushi Ogasawara; Michiko Fujimori; Junpei Kawata; Tohru Dairi
    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 26, 15, 3662, 3664, Aug. 2016, [Peer-reviewed]
    English, Scientific journal
  • Exploring Peptide Ligase Orthologs in Actinobacteria-Discovery of Pseudopeptide Natural Products, Ketomemicins
    Yasushi Ogasawara; Junpei Kawata; Motoyoshi Noike; Yasuharu Satoh; Kazuo Furihata; Tohru Dairi
    ACS CHEMICAL BIOLOGY, 11, 6, 1686, 1692, Jun. 2016, [Peer-reviewed]
    English, Scientific journal
  • Structure and activity relationships of the anti-Mycobacterium antibiotics resorcinomycin and pheganomycin
    Yasushi Ogasawara; Koichi Ooya; Michiko Fujimori; Motoyoshi Noike; Tohru Dairi
    JOURNAL OF ANTIBIOTICS, 69, 2, 119, 120, Feb. 2016, [Peer-reviewed]
    English, Scientific journal
  • High-quality draft genome sequence of actinobacterium Kibdelosporangium sp. MJ126-NF4, producer of type II polyketide azicemicins, using Illumina and PacBio technologies
    Yasushi Ogasawara; Norah Torrez-Martinez; Anthony D. Aragon; Benjamin J. Yackley; Jessica A. Weber; Anitha Sundararajan; Thiruvarangan Ramaraj; Jeremy S. Edwards; Charles E. Melançon
    Genome Announcements, 3, 2, American Society for Microbiology, 2016, [Peer-reviewed]
    English, Scientific journal
  • High-quality draft genome sequence of actinobacterium Kibdelosporangium sp. MJ126-NF4, producer of type II polyketide azicemicins, using Illumina and PacBio technologies
    Yasushi Ogasawara; Norah Torrez-Martinez; Anthony D. Aragon; Benjamin J. Yackley; Jessica A. Weber; Anitha Sundararajan; Thiruvarangan Ramaraj; Jeremy S. Edwards; Charles E. Melançon
    Genome Announcements, 3, 2, American Society for Microbiology, 2016, [Peer-reviewed]
    English, Scientific journal
  • Expanding our Understanding of Sequence-Function Relationships of Type II Polyketide Biosynthetic Gene Clusters: Bioinformatics-Guided Identification of Frankiamicin A from Frankia sp. EAN1pec (vol 10, e0121505, 2015)
    Yasushi Ogasawara; Benjamin J. Yackley; Jacob A. Greenberg; Snezna Rogelj; Charles E. Melancon
    PLOS ONE, 10, 6, e0121505, Jun. 2015, [Peer-reviewed]
    English
  • Identification and analysis of the resorcinomycin biosynthetic gene cluster
    Koichi Ooya; Yasushi Ogasawara; Motoyoshi Noike; Tohru Dairi
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 79, 11, 1833, 1837, 2015, [Peer-reviewed]
    English, Scientific journal
  • GenK-catalyzed C-6' methylation in the biosynthesis of gentamicin: isolation and characterization of a cobalamin-dependent radical SAM enzyme.
    Kim HJ; McCarty RM; Ogasawara Y; Liu YN; Mansoorabadi SO; LeVieux J; Liu HW
    Journal of the American Chemical Society, 135, 22, 8093, 8096, Jun. 2013, [Peer-reviewed]
    Kim HJ, McCarty RM, Ogasawara Y, Liu YN, Mansoorabadi SO, LeVieux J, Liu HW, Journal of the American Chemical Society, 2013, vol. 135, no. 22, pp. 8093-8096, 2013
  • Radical SAM enzymes in the biosynthesis of sugar-containing natural products.
    Ruszczycky MW; Ogasawara Y; Liu HW
    Biochimica et biophysica acta, 1824, 11, 1231, 1244, Nov. 2012, [Peer-reviewed]
    Ruszczycky MW, Ogasawara Y, Liu HW, Biochimica et biophysica acta, 2012, vol. 1824, no. 11, pp. 1231-1244, 2012
  • A Biosynthetic Pathway for BE-7585A, a 2-Thlosugar-Containing Angucycline-Type Natural Product
    Eita Sasaki; Yasushi Ogasawara; Hung-wen Liu
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132, 21, 7405, 7417, Jun. 2010, [Peer-reviewed]
    English, Scientific journal
  • Biosynthesis of Spinosyn in Saccharopolyspora spinosa: Synthesis of Permethylated Rhamnose and Characterization of the Functions of SpnH, Spnl, and SpnK
    Hak Joong Kim; Jess A. White-Phillip; Yasushi Ogasawara; Nara Shin; Eta A. Isiorho; Hung-wen Liu
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132, 9, 2901, +, Mar. 2010, [Peer-reviewed]
    English, Scientific journal
  • Biosynthetic Studies of Aziridine Formation in Azicemicins
    Yasushi Ogasawara; Hung-wen Liu
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131, 50, 18066, +, Dec. 2009, [Peer-reviewed]
    English, Scientific journal
  • Involvement of glutamate mutase in the biosynthesis of the unique starter unit of the macrolactam polyketide antibiotic vicenistatin
    Y Ogasawara; K Kakinuma; T Eguchi
    JOURNAL OF ANTIBIOTICS, 58, 7, 468, 472, Jul. 2005, [Peer-reviewed]
    English, Scientific journal
  • Cloning, sequencing, and functional analysis of the biosynthetic gene cluster of macrolactam antibiotic vicenistatin in Streptomyces halstedii
    Y Ogasawara; K Katayama; A Minami; M Otsuka; T Eguchi; K Kakinuma
    CHEMISTRY & BIOLOGY, 11, 1, 79, 86, Jan. 2004, [Peer-reviewed]
    English, Scientific journal
■ Other Activities and Achievements
■ Syllabus
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 生命分子化学特論, 2024年, 修士課程, 総合化学院
  • 生命分子化学特論, 2024年, 修士課程, 工学院
  • 応用生物化学（生合成工学）, 2024年, 修士課程, 総合化学院
  • 生命分子化学特論, 2024年, 博士後期課程, 工学院
  • 応用化学学生実験Ⅲ, 2024年, 学士課程, 工学部
  • 生物工学概論, 2024年, 学士課程, 工学部
  • 生化学Ⅰ, 2024年, 学士課程, 工学部
■ Affiliated academic society
  • The Society for Biotechnology, Japan
  • SOCIETY FOR ACTINOMYCETES JAPAN
  • JAPAN SOCIETY FOR BIOSCIENCE, BIOTECHNOLOGY, AND AGROCHEMISTRY
  • 日本ペプチド学会
■ Research Themes
  • Dissecting biosynthetic machineries of natural peptides leading to structural and functional diversities.
    Grants-in-Aid for Scientific Research
    27 Apr. 2022 - 31 Mar. 2027
    大利 徹; 小笠原 泰志; 森田 洋行; 濱野 吉十
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 22H04976
  • Enhancing the diversity of peptides by amino acids with reactive functional groups
    Grants-in-Aid for Scientific Research
    Jun. 2022 - Mar. 2027
    勝山 陽平; 小笠原 泰志
    Japan Society for the Promotion of Science, Grant-in-Aid for Transformative Research Areas (A), The University of Tokyo, 22H05130
  • 生理活性天然物の生合成に関わる三員環構築酵素の精密解析
    科学研究費助成事業
    01 Apr. 2023 - 31 Mar. 2026
    小笠原 泰志
    生理活性物質として単離された天然物有機化合物には、シクロプロパンやエポキシド、アジリジンなどの三員環構造を有するものが多く存在する。三員環構造は、大きなひずみに起因する反応性の高さに加え、配座自由度の制限により標的分子への選択性向上や結合安定化に寄与するため、多くの場合、天然物の生理活性発現に重要である。本研究ではその生合成に関わる酵素の反応解析を行った。
    （１）ベラクトシンやホルマオマイシンはシクロプロピルアラニン構造を有する。代表者はその生合成機構を解析し、BelK/HrmIがL-リジンから6-ニトロノルロイシンへの酸化反応を触媒し、BelL/HrmJが6-ニトロノルロイシンからニトロシクロプロピルアラニンへの環化反応を触媒することを明らかにした。シクロプロピルアラニン構造を有する構造は２つのみが知られていたが、様々な菌に上記遺伝子の相同遺伝子が分布していた。そこで、相同遺伝子を含む遺伝子クラスターの中でクラスターに含まれる遺伝子がユニークであった遺伝子クラスターを幾つか選択し、それぞれ遺伝子の破壊株を構築して、代謝産物をHPLC で分析した。その結果一株については野生株にしか見られない代謝産物のピークが見いだされた。
    （２）マイトマイシン類はアジリジン構造を有する抗腫瘍抗生物質である。その生合成について、アミノヒドロキシ安息香酸とN-アセチルグルコサミンを起点として、前者のアシルキャリアタンパク質へのロードに続いてグリコシル化反応が起こることを見出した。続く３つの反応についてもin vivo, in vitro実験で明らかにした。
    日本学術振興会, 基盤研究(B), 北海道大学, 23K26838
  • 生理活性天然物の生合成に関わる三員環構築酵素の精密解析
    科学研究費助成事業 基盤研究(B)
    01 Apr. 2023 - 31 Mar. 2026
    小笠原 泰志
    日本学術振興会, 基盤研究(B), 北海道大学, 23H02145
  • Analysis of new peptide epimerases for the biosynthesis of peptide natural products
    Grants-in-Aid for Scientific Research
    01 Apr. 2018 - 31 Mar. 2021
    Ogasawara Yasushi
    While most natural peptides consist of L-amino acids, D-amino acids are also widely identified both in primary and secondary metabolites. The presence of D-amino acids in secondary metabolites is generally a hallmark of peptides biosynthesized via non-ribosomal peptide synthetases and only a few peptide epimerases that introduce D-amino acids residue into polypeptides via epimerization have been reported. In this study, we investigated two novel types of peptide epimerases and revealed novel enzyme chemistry.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18K05449
  • Exploring and functional analysis of peptide ligase orthologs
    Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    01 Apr. 2016 - 31 Mar. 2018
    Ogasawara Yasushi
    We previously identified a novel amide bond forming enzyme (peptide ligase, PGM1) responsible for the biosynthesis of peptide antibiotic, pheganomycin. In this study, we studied PGM1 orthologs found in actinobacteria. We first analyzed a ortholog (KtmD) responsible for the biosynthesis of previously discovered novel pseudotripeptides, ketomemicins, which possess a C-terminal pseudodipeptide connected with a carbonylmethylene instead of an amide bond. We showed that KtmD was a novel dipeptide ligase catalyzing amide bond formation between amidino-arginine and pseudodipeptides in the final step of biosynthesis. We next examined the biosynthesis of pseudodipeptide structure in ketomemicins and fully characterized the biosynthetic pathway of the pseudodipeptide in vitro. Furthermore, we investigated other orthologs to probe the functions of these genes. We heterologously expressed ortholog-containing gene clusters in Streptomyces lividans and detected several specific metabolites.
    Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 16K18692
  • Biosynthesis of the Carbonylmethylene Structure Found in a Class of Pseudotripeptides, Ketomemicins
    Grants-in-Aid for Scientific Research
    01 Apr. 2015 - 31 Mar. 2018
    Dairi Tohru; SATOH YASUHARU; OGASAWARA YASUSHI; MORITA HIROYUKI
    We recently discovered novel pseudotripeptides, ketomemicins, which possess a C-terminal pseudodipeptide connected with a carbonyl methylene instead of an amide bond. The carbonyl methylene structure is stable than amide bond and its biological significance has been shown in several natural and synthetic compounds. Despite the biological significances of these compounds, little is known about its biosynthetic machinery. We therefore examined it by in vitro studies with recombinant enzymes. Consequently, an aldolase, dehydratase, PLP-dependent glycine-C-acetyltransferase, and dehydrogenase were revealed to be involved in the formation of the pseudodipeptide with malonyl-CoA and phenylpyruvate as starter substrates.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 15H03110
■ Academic and Social Contribution Activities/Other
Industrial Property Rights
  • 日本農芸化学会2025年度大会実行委員
    Mar. 2025 - Mar. 2025
    Planning etc
    Competition etc
    北海道大学大学院農学研究院 園山 慶 教授
  • 2019年度 日本放線菌学会第34回大会実行委員
    Sep. 2019 - Sep. 2019
    Planning etc
    Competition etc
    北海道大学大学院工学研究院 大利 徹 教授
  • 第59回天然有機化合物討論会実行委員
    Oct. 2017 - Oct. 2017
    Planning etc
    Competition etc
    北海道大学大学院薬学研究院 市川 聡 教授
  • 2014年度 日本生物工学会大会実行委員
    Jun. 2014 - Jun. 2014
    Planning etc
    Competition etc
    北海道大学大学院工学研究院 髙木 睦 教授