Presentation Information
[1MENP-11]AmCP-dependent biosynthesis of maleimycin
○Ayako Yoshida1,2, Makoto Nishiyama1,2 (1. GSALS, UTokyo (Japan), 2. CRIIM, UTokyo (Japan))
Keywords:
amino-group carrier protein,biosynthesis,Streptomyces
[Purpose]
We have identified an amino-group carrier protein (AmCP) and demonstrated that it is utilized for lysine and arginine biosynthesis in thermophilic bacteria and archaea. In addition, we have shown that AmCP is involved in the biosynthesis of non-proteinogenic amino acids in actinomycetes, serving as an intermediate for secondary metabolite production. Genome mining further revealed that a wide variety of bacteria possess gene clusters containing amcp, suggesting that AmCP-dependent systems may contribute to the expansion of structural diversity in natural products. This study aims to elucidate the AmCP-dependent biosynthetic pathway of maleimycin, an antibiotic with a unique bicyclic structure containing a maleimide moiety.
[Method]
We identified the maleimycin biosynthetic gene cluster containing amcp through genome mining followed by analysis of its associated metabolites. The biosynthetic pathway of maleimycin was investigated through a combination of in vivo and in vitro analyses. In addition, structural analysis of a key enzyme and structure-guided mutagenesis were carried out to gain mechanistic insights into the reaction involved.
[Results]
We elucidated the AmCP-dependent biosynthetic pathway of maleimycin. The pathway can be divided into two phases: the AmCP-dependent formation of a novel non-proteinogenic amino acid intermediate, followed by its conversion to maleimycin. A notable feature of the first half of the pathway is that the conserved C-terminal glutamate residue of AmCP, which is typically required for substrate loading, is replaced by glutamine. Furthermore, we identified a single enzyme that catalyzes both the conversion of this glutamine to glutamate and the release of the product from AmCP. Another distinctive feature is the requirement for an unprecedented three-carbon chain elongation reaction using C4-carbon substrate via a decarboxylation-coupled C-C bond formation to generate the intermediate synthesized on AmCP. Structural analysis of the responsible enzyme, combined with mutational analyses, enabled us to propose a plausible reaction mechanism.
[Consideration]
The identification of this three-carbon extension reaction expands the chemical diversity of amino acid building blocks generated via AmCP systems. Comparison with previously characterized systems suggests that the highly reactive AmCP-semialdehyde intermediate serves as a key determinant of this chemical expansion of the natural products with structural diversity.
[Conclusion]
These findings provide new insights into the strategy underlying AmCP-mediated biosynthesis and highlight its potential as a platform for generating structurally diverse natural products.
We have identified an amino-group carrier protein (AmCP) and demonstrated that it is utilized for lysine and arginine biosynthesis in thermophilic bacteria and archaea. In addition, we have shown that AmCP is involved in the biosynthesis of non-proteinogenic amino acids in actinomycetes, serving as an intermediate for secondary metabolite production. Genome mining further revealed that a wide variety of bacteria possess gene clusters containing amcp, suggesting that AmCP-dependent systems may contribute to the expansion of structural diversity in natural products. This study aims to elucidate the AmCP-dependent biosynthetic pathway of maleimycin, an antibiotic with a unique bicyclic structure containing a maleimide moiety.
[Method]
We identified the maleimycin biosynthetic gene cluster containing amcp through genome mining followed by analysis of its associated metabolites. The biosynthetic pathway of maleimycin was investigated through a combination of in vivo and in vitro analyses. In addition, structural analysis of a key enzyme and structure-guided mutagenesis were carried out to gain mechanistic insights into the reaction involved.
[Results]
We elucidated the AmCP-dependent biosynthetic pathway of maleimycin. The pathway can be divided into two phases: the AmCP-dependent formation of a novel non-proteinogenic amino acid intermediate, followed by its conversion to maleimycin. A notable feature of the first half of the pathway is that the conserved C-terminal glutamate residue of AmCP, which is typically required for substrate loading, is replaced by glutamine. Furthermore, we identified a single enzyme that catalyzes both the conversion of this glutamine to glutamate and the release of the product from AmCP. Another distinctive feature is the requirement for an unprecedented three-carbon chain elongation reaction using C4-carbon substrate via a decarboxylation-coupled C-C bond formation to generate the intermediate synthesized on AmCP. Structural analysis of the responsible enzyme, combined with mutational analyses, enabled us to propose a plausible reaction mechanism.
[Consideration]
The identification of this three-carbon extension reaction expands the chemical diversity of amino acid building blocks generated via AmCP systems. Comparison with previously characterized systems suggests that the highly reactive AmCP-semialdehyde intermediate serves as a key determinant of this chemical expansion of the natural products with structural diversity.
[Conclusion]
These findings provide new insights into the strategy underlying AmCP-mediated biosynthesis and highlight its potential as a platform for generating structurally diverse natural products.
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