Biosynthesis of Long-Chain N-Acyl Amide by a Truncated Polyketide Synthase-Nonribosomal Peptide Synthetase Hybrid Megasynthase in Fungi

J Am Chem Soc. 2018 Jan 31;140(4):1271-1274. doi: 10.1021/jacs.7b13350. Epub 2018 Jan 23.

Abstract

Truncated iterative polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) megasynthases in which only the C domain is present are widespread in fungi, yet nearly all members have unknown functions. Bioinformatics analysis showed that the C domains of such PKS-C enzymes are noncanonical due to substitution at the second histidine in the active site HHxxxDG motif. Here, we used genome mining strategy to characterize a cryptic PKS-C hybrid from Talaromyces wortmanii and discovered the products are reduced long-chain polyketides amidated with a specific ω-amino acid 5-aminopentanoic acid (5PA). The wortmanamides resemble long-chain N-acyl-amide signaling lipids that target diverse receptors including GPCRs. The noncanonical C domain of this PKS-C hybrid was also demonstrated to be a bona fide condensation domain that specifically selects 5PA and catalyzes amidation to release polyketide chain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry
  • Amides / metabolism*
  • Molecular Conformation
  • Peptide Synthases / chemistry
  • Peptide Synthases / metabolism*
  • Polyketide Synthases / chemistry
  • Polyketide Synthases / metabolism*
  • Talaromyces / enzymology*
  • Talaromyces / metabolism

Substances

  • Amides
  • Polyketide Synthases
  • Peptide Synthases
  • non-ribosomal peptide synthase