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Publication Abstract from PubMed

Assembly-line polyketide synthases (PKSs) are molecular factories that produce diverse metabolites with wide-ranging biological activities. PKSs usually work by constructing and modifying the polyketide backbone successively. Here, we present the cryo-EM structure of CalA3, a chain release PKS module without an ACP domain, and its structures with amidation or hydrolysis products. The domain organization reveals a unique "infinity"-shaped dimeric architecture with five connected domains. The catalytic region tightly contacts the structural region, resulting in two stabilized chambers with nearly perfect symmetry while the N-terminal docking domain is flexible. The structures of the ketosynthase (KS) domain illustrate how the conserved key residues that canonically catalyze C-C bond formation can be tweaked to mediate C-N bond formation, revealing the engineering adaptability of assembly-line polyketide synthases for the production of novel pharmaceutical agents.

C-N bond formation by a polyketide synthase.,Wang J, Wang X, Li X, Kong L, Du Z, Li D, Gou L, Wu H, Cao W, Wang X, Lin S, Shi T, Deng Z, Wang Z, Liang J Nat Commun. 2023 Mar 10;14(1):1319. doi: 10.1038/s41467-023-36989-w. PMID:36899013^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.