Radical SAM Enzyme QmpB Installs Two 9-Membered Ring Sactionine Macrocycles during Biogenesis of a Ribosomal Peptide Natural Product.

TitleRadical SAM Enzyme QmpB Installs Two 9-Membered Ring Sactionine Macrocycles during Biogenesis of a Ribosomal Peptide Natural Product.
Publication TypeJournal Article
Year of Publication2021
AuthorsCaruso, A, Seyedsayamdost, MR
JournalJ Org Chem
Volume86
Issue16
Pagination11284-11289
Date Published2021/08/20
ISSN1520-6904
Abstract

We report the reaction catalyzed by QmpB, a new radical -adenosylmethionine enzyme encoded by a ribosomal peptide natural product gene cluster in . Using isotopic labeling, site-directed mutagenesis, high-resolution mass spectrometry, and multidimensional NMR spectroscopy, we show that QmpB installs two 9-membered ring sactionine bridges, connecting a Cys residue with an upstream Asn via an α-thioether bridge, with the two macrocycles separated by a single residue. QmpB is only the second type II sactionine synthase characterized to date.

DOI10.1021/acs.joc.1c01507
Alternate JournalJ Org Chem
PubMed ID34351169