Title | Crochelins: Siderophores with an Unprecedented Iron-Chelating Moiety from the Nitrogen-Fixing Bacterium Azotobacter chroococcum. |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | Baars, O, Zhang, X, Gibson, MI, Stone, AT, Morel, FMM, Seyedsayamdost, MR |
Journal | Angew Chem Int Ed Engl |
Volume | 57 |
Issue | 2 |
Pagination | 536-541 |
Date Published | 2018 Jan 08 |
ISSN | 1521-3773 |
Keywords | Azotobacter, Chromatography, High Pressure Liquid, Iron Chelating Agents, Mass Spectrometry, Molecular Structure, Nitrogen Fixation, Siderophores |
Abstract | <p>Microbes use siderophores to access essential iron resources in the environment. Over 500 siderophores are known, but they utilize a small set of common moieties to bind iron. Azotobacter chroococcum expresses iron-rich nitrogenases, with which it reduces N . Though an important agricultural inoculant, the structures of its iron-binding molecules remain unknown. Here, the "chelome" of A. chroococcum is examined using small molecule discovery and bioinformatics. The bacterium produces vibrioferrin and amphibactins as well as a novel family of siderophores, the crochelins. Detailed characterization shows that the most abundant member, crochelin A, binds iron in a hexadentate fashion using a new iron-chelating γ-amino acid. Insights into the biosynthesis of crochelins and the mechanism by which iron may be removed upon import of the holo-siderophore are presented. This work expands the repertoire of iron-chelating moieties in microbial siderophores.</p> |
DOI | 10.1002/anie.201709720 |
Alternate Journal | Angew Chem Int Ed Engl |
PubMed ID | 29134779 |