Structural insights into a novel family of integral membrane siderophore reductases
Inokentijs Josts, Katharina Veith, Vincent Normant, Isabelle J. Schalk, Henning Tidow
Abstract
Significance Secretion of siderophores allows most microbes to assimilate ferric ions into their biological processes. Siderophores must be taken up into the cells, and chelated iron must be released. Here, we present the structure of an inner membrane siderophore reductase, FoxB, which is involved in the uptake of iron from ferrioxamine siderophores in Pseudomonas aeruginosa . Our structure reveals FoxB to be a di-heme membrane protein, which is able to reduce the iron in chelated ferric-siderophore complexes. In combination with in vivo uptake studies, these results offer insights into the function of this poorly characterized membrane protein family and its role in iron release from bacterial siderophores.