Premium
Enzymatic Amide Tailoring Promotes Retro‐Aldol Amino Acid Conversion To Form the Antifungal Agent Aspirochlorine
Author(s) -
Tsunematsu Yuta,
Maeda Naoya,
Yokoyama Mamoru,
Chankhamjon Pranatchareeya,
Watanabe Kenji,
Scherlach Kirstin,
Hertweck Christian
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201806740
Subject(s) - moiety , chemistry , aldol reaction , biochemistry , peptide , heterologous expression , enzyme , stereochemistry , peptide bond , aspergillus oryzae , biosynthesis , combinatorial chemistry , recombinant dna , gene , catalysis
Aspirochlorine is an unusual antifungal cyclopeptide produced by Aspergillus oryzae, an important mold used for food fermentation. Whereas its structure suggested that a non‐ribosomal peptide synthetase assembles the cyclopeptide from phenylalanine and glycine building blocks, labeling studies indicated that one Phe moiety is transformed into Gly after peptide formation. By means of genetic engineering, heterologous expression, biotransformations, and in vitro assays, we dissected and reconstituted four crucial steps in aspirochlorine biosynthesis, which involve two cytochrome P450 monooxygenases, (AclL and AclO), a methyltransferase (AclU), and a halogenase (AclH). We found that the installation of the N‐methoxylation of the peptide bond sets the stage for a retro‐aldol reaction that leads to the Phe‐to‐Gly conversion. The substrate scopes of the dedicated enzymes as well as bioassays revealed that the peptide editing has evolved to optimize the antifungal action of the natural product.