|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|
|Date Published||2018 Jan 08|
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.
|Alternate Journal||Angew. Chem. Int. Ed. Engl.|