Issue 6, 2015

Metal selectivity by the virulence-associated yersiniabactin metallophore system

Abstract

Uropathogenic Escherichia coli secrete siderophores during human infections. Although siderophores are classically defined by their ability to bind iron(III) ions, the virulence-associated siderophore yersiniabactin was recently found to bind divalent copper ions during urinary tract infections. Here we use a mass spectrometric approach to determine the extent of non-iron(III) metal interactions by yersiniabactin and its TonB-dependent outer membrane importer FyuA. In addition to copper, iron and gallium ions, yersiniabactin was also observed to form stable nickel, cobalt, and chromium ion complexes. In E. coli, copper(II) and all other non-iron(III) yersiniabactin complexes were imported by FyuA in a TonB-dependent manner. Among metal–yersiniabactin complexes, copper(II) yersiniabactin is predicted to be structurally distinctive and was the only complex not to competitively inhibit iron(III) yersiniabactin import. These results are consistent with yersiniabactin as part of a metallophore system able to prioritize iron(III) complex uptake in high copper environments.

Graphical abstract: Metal selectivity by the virulence-associated yersiniabactin metallophore system

Supplementary files

Article information

Article type
Paper
Submitted
19 Des 2014
Accepted
25 Mac 2015
First published
25 Mac 2015

Metallomics, 2015,7, 1011-1022

Author version available

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