共查询到20条相似文献,搜索用时 15 毫秒
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Isao Fujii Makoto Hashimoto Kaori Konishi Akiko Unezawa Haruka Sakuraba Kenta Suzuki Harue Tsushima Miho Iwasaki Satsuki Yoshida Akane Kudo Rina Fujita Aika Hichiwa Koharu Saito Takashi Asano Jun Ishikawa Daigo Wakana Yukihiro Goda Ayumi Watanabe Mamoru Watanabe Yui Masumoto Junichiro Kanazawa Hajime Sato Masanobu Uchiyama 《Angewandte Chemie (International ed. in English)》2020,59(22):8464-8470
Shimalactones A and B are neuritogenic polyketides possessing characteristic oxabicyclo[2.2.1]heptane and bicyclo[4.2.0]octadiene ring systems that are produced by the marine fungus Emericella variecolor GF10. We identified a candidate biosynthetic gene cluster and conducted heterologous expression analysis. Expression of ShmA polyketide synthase in Aspergillus oryzae resulted in the production of preshimalactone. Aspergillus oryzae and Saccharomyces cerevisiae transformants expressing ShmA and ShmB produced shimalactones A and B, thus suggesting that the double bicyclo‐ring formation reactions proceed non‐enzymatically from preshimalactone epoxide. DFT calculations strongly support the idea that oxabicyclo‐ring formation and 8π‐6π electrocyclization proceed spontaneously after opening of the preshimalactone epoxide ring through protonation. We confirmed the formation of preshimalactone epoxide in vitro, followed by its non‐enzymatic conversion to shimalactones in the dark. 相似文献
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Rational Control of Polyketide Extender Units by Structure‐Based Engineering of a Crotonyl‐CoA Carboxylase/Reductase in Antimycin Biosynthesis 下载免费PDF全文
Lihan Zhang Takahiro Mori Qingfei Zheng Dr. Takayoshi Awakawa Yan Yan Prof. Wen Liu Prof. Ikuro Abe 《Angewandte Chemie (International ed. in English)》2015,54(45):13462-13465
Bioengineering of natural product biosynthesis is a powerful approach to expand the structural diversity of bioactive molecules. However, in polyketide biosynthesis, the modification of polyketide extender units, which form the carbon skeletons, has remained challenging. Herein, we report the rational control of polyketide extender units by the structure‐based engineering of a crotonyl‐CoA carboxylase/reductase (CCR), in the biosynthesis of antimycin. Site‐directed mutagenesis of the CCR enzyme AntE, guided by the crystal structure solved at 1.5 Å resolution, expanded its substrate scope to afford indolylmethylmalonyl‐CoA by the V350G mutation. The mutant A182L selectively catalyzed carboxylation over the regular reduction. Furthermore, the combinatorial biosynthesis of heterocycle‐ and substituted arene‐bearing antimycins was achieved by an engineered Streptomyces strain bearing AntEV350G. These findings deepen our understanding of the molecular mechanisms of the CCRs, which will serve as versatile biocatalysts for the manipulation of building blocks, and set the stage for the rational design of polyketide biosynthesis. 相似文献
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Yu Zhou Dr. Evan N. Mirts Sangdo Yook Dr. Matthew Waugh Rachel Martini Prof. Yong-Su Jin Prof. Yi Lu 《Angewandte Chemie (International ed. in English)》2023,62(5):e202212440
Engineering enzymes with novel reactivity and applying them in metabolic pathways to produce valuable products are quite challenging due to the intrinsic complexity of metabolic networks and the need for high in vivo catalytic efficiency. Triacetic acid lactone (TAL), naturally generated by 2-pyrone synthase (2PS), is a platform molecule that can be produced via microbial fermentation and further converted into value-added products. However, these conversions require extra synthetic steps under harsh conditions. We herein report a biocatalytic system for direct generation of TAL derivatives under mild conditions with controlled chemoselectivity by rationally engineering the 2PS active site and then rewiring the biocatalytic pathway in the metabolic network of E. coli to produce high-value products, such as kavalactone precursors, with yields up to 17 mg/L culture. Computer modeling indicates sterics and hydrogen-bond interactions play key roles in tuning the selectivity, efficiency and yield. 相似文献
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Biosynthesis of the Structurally Unique Polycyclopropanated Polyketide–Nucleoside Hybrid Jawsamycin (FR‐900848) 下载免费PDF全文
Dr. Tomoshige Hiratsuka Hideaki Suzuki Ryo Kariya Takashi Seo Dr. Atsushi Minami Prof. Dr. Hideaki Oikawa 《Angewandte Chemie (International ed. in English)》2014,53(21):5423-5426
The biosynthetic gene cluster of antifungal agent jawsamycin (FR‐900848) has been identified by heterologous expression. A series of gene inactivations and in vitro and in vivo analysis of key enzymes in the biosynthetic pathway established their functions. A novel mechanism involving a radical S‐adenosyl methionine (SAM) cyclopropanase collaborating with an iterative polyketide synthase is proposed for the construction of the unique polycyclopropanated backbone. Our reconstitution system sets the stage for studying the catalytic mechanism of this intriguing contiguous cyclopropanation. 相似文献
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Iterative Assembly of Two Separate Polyketide Chains by the Same Single‐Module Bacterial Polyketide Synthase in the Biosynthesis of HSAF 下载免费PDF全文
Dr. Yaoyao Li Haotong Chen Yanjiao Ding Yunxuan Xie Dr. Haoxin Wang Prof. Dr. Ronald L. Cerny Prof. Dr. Yuemao Shen Prof. Dr. Liangcheng Du 《Angewandte Chemie (International ed. in English)》2014,53(29):7524-7530
Antifungal HSAF (heat‐stable antifungal factor, dihydromaltophilin) is a polycyclic tetramate macrolactam from the biocontrol agent Lysobacter enzymogenes. Its biosynthetic gene cluster contains only a single‐module polyketide synthase–nonribosomal peptide synthetase (PKS‐NRPS), although two separate hexaketide chains are required to assemble the skeleton. To address the unusual biosynthetic mechanism, we expressed the biosynthetic genes in two “clean” strains of Streptomyces and showed the production of HSAF analogues and a polyene tetramate intermediate. We then expressed the PKS module in Escherichia coli and purified the enzyme. Upon incubation of the enzyme with acyl‐coenzyme A and reduced nicotinamide adenine dinucleotide phosphate (NADPH), a polyene was detected in the tryptic acyl carrier protein (ACP). Finally, we incubated the polyene–PKS with the NRPS module in the presence of ornithine and adenosine triphosphate (ATP), and we detected the same polyene tetramate as that in Streptomyces transformed with the PKS‐NRPS alone. Together, our results provide evidence for an unusual iterative biosynthetic mechanism for bacterial polyketide–peptide natural products. 相似文献
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Enzymology of Anthraquinone‐γ‐Pyrone Ring Formation in Complex Aromatic Polyketide Biosynthesis 下载免费PDF全文
Dr. Xian‐Feng Hou Dr. Yu‐Jiao Song Dr. Mei Zhang Dr. Wenxian Lan Dr. Song Meng Dr. Chunxi Wang Dr. Hai‐Xue Pan Prof. Dr. Chunyang Cao Prof. Dr. Gong‐Li Tang 《Angewandte Chemie (International ed. in English)》2018,57(41):13475-13479
Aromatic‐fused γ‐pyrones are structural features of many bioactive natural products and valid scaffolds for medicinal chemistry. However, the enzymology of their formation has not been completely established. Now it is demonstrated that TxnO9, a CalC‐like protein belonging to a START family, functions as an unexpected anthraquinone‐γ‐pyrone synthase involved in the biosynthesis of antitumor antibiotic trioxacarcin A (TXN‐A). Structural analysis by NMR identified a likely substrate/product‐binding mode and putative key active sites of TxnO9, which allowed an enzymatic mechanism to be proposed. Moreover, a subset of uncharacterized homologous proteins bearing an unexamined Lys‐Thr dyad exhibit the same function. Therefore, the functional assignment and mechanistic investigation of this γ‐pyrone synthase elucidated an undescribed step in TXN‐A biosynthesis, and the discovery of this new branch of polyketide heterocyclases expands the functions of the START superfamily. 相似文献
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The Interplay between a Multifunctional Dehydratase Domain and a C‐Methyltransferase Effects Olefin Shift in Ambruticin Biosynthesis 下载免费PDF全文
Gesche Berkhan Dr. Christian Merten Claudia Holec Prof. Dr. Frank Hahn 《Angewandte Chemie (International ed. in English)》2016,55(43):13589-13592
The olefin shift is an important modification during polyketide biosynthesis. Particularly for type I cis‐AT PKS, little information has been gained on the enzymatic mechanisms involved. We present our in vitro investigations on the olefin shift occurring during ambruticin biosynthesis. The unique, multifunctional domain AmbDH4 catalyzes consecutive dehydration, epimerization, and enoyl isomerization. The resulting 3‐enethioate is removed from the equilibrium by α‐methylation catalyzed by the highly specific C‐methyltransferase AmbM. This thermodynamically unfavorable overall process is enabled by the high, concerted substrate specificity of the involved enzymes. AmbDH4 shows close relationship to DH domains and initial mechanistic studies suggest that the olefin shift occurs via a similar proton‐shuttling mechanism as previously described for EI domains from trans‐AT‐PKS. 相似文献
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Mechanistic Insights into Polycycle Formation by Reductive Cyclization in Ikarugamycin Biosynthesis 下载免费PDF全文
Dr. Guangtao Zhang Dr. Wenjun Zhang Dr. Qingbo Zhang Ting Shi Liang Ma Dr. Yiguang Zhu Dr. Sumei Li Dr. Haibo Zhang Prof. Dr. Yi‐Lei Zhao Prof. Dr. Rong Shi Prof. Dr. Changsheng Zhang 《Angewandte Chemie (International ed. in English)》2014,53(19):4840-4844
Ikarugamycin is a member of the polycyclic tetramate macrolactams (PTMs) family of natural products with diverse biological activities. The biochemical mechanisms for the formation of polycyclic ring systems in PTMs remain elusive. The enzymatic mechanism of constructing an inner five‐membered ring in ikarugamycin is reported. A three‐gene‐cassette ikaABC from the marine‐derived Streptomyces sp. ZJ306 is sufficient for conferring ikarugamycin production in a heterologous host. IkaC catalyzes a reductive cyclization reaction to form the inner five‐membered ring by a Michael addition‐like reaction. This study provides the first biochemical evidence for polycycle formation in PTMs and suggests a reductive cyclization strategy which may be potentially applicable in general to the corresponding ring formation in other PTMs. 相似文献
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Heterologous Production of Fungal Maleidrides Reveals the Cryptic Cyclization Involved in their Biosynthesis 下载免费PDF全文
Dr. Katherine Williams Agnieszka J. Szwalbe Dr. Nicholas P. Mulholland Dr. Jason L. Vincent Dr. Andrew M. Bailey Prof. Christine L. Willis Prof. Thomas J. Simpson Prof. Russell J. Cox 《Angewandte Chemie (International ed. in English)》2016,55(23):6784-6788
Fungal maleidrides are an important family of bioactive secondary metabolites that consist of 7, 8, or 9‐membered carbocycles with one or two fused maleic anhydride moieties. The biosynthesis of byssochlamic acid (a nonadride) and agnestadride A (a heptadride) was investigated through gene disruption and heterologous expression experiments. The results reveal that the precursors for cyclization are formed by an iterative highly reducing fungal polyketide synthase supported by a hydrolase, together with two citrate‐processing enzymes. The enigmatic ring formation is catalyzed by two proteins with homology to ketosteroid isomerases, and assisted by two proteins with homology to phosphatidylethanolamine‐binding proteins. 相似文献