Open AccessCharacterization of a Copper-Chelating Natural Product from the Methanotroph Methylosinus sp. LW3
Author(s) -
Yun Ji Park,
Gerri M. Roberts,
Rana Montaser,
Grace E. Kenney,
Paul M. Thomas,
Neil L. Kelleher,
Amy C. Rosenzweig
Publication year - 2021
Publication title -
biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.43
H-Index - 253
eISSN - 1520-4995
pISSN - 0006-2960
DOI - 10.1021/acs.biochem.1c00443
Subject(s) - methanotroph , chemistry , operon , cysteine , enzyme , biochemistry , stereochemistry , escherichia coli , anaerobic oxidation of methane , catalysis , gene
Methanobactins (Mbns) are ribosomally produced, post-translationally modified peptidic natural products that bind copper with high affinity. Methanotrophic bacteria use Mbns to acquire copper needed for enzymatic methane oxidation. Despite the presence of Mbn operons in a range of methanotroph and other bacterial genomes, few Mbns have been isolated and structurally characterized. Here we report the isolation of a novel Mbn from the methanotroph Methylosinus ( Ms .) sp. LW3. Mass spectrometric and nuclear magnetic resonance spectroscopic data indicate that this Mbn, the largest characterized to date, consists of a 13-amino acid backbone modified to include pyrazinedione/oxazolone rings and neighboring thioamide groups derived from cysteine residues. The pyrazinedione ring is more stable to acid hydrolysis than the oxazolone ring and likely protects the Mbn from degradation. The structure corresponds exactly to that predicted on the basis of the Ms . sp. LW3 Mbn operon content, providing support for the proposed role of an uncharacterized biosynthetic enzyme, MbnF, and expanding the diversity of known Mbns.