Iron homeostasis and iron-sulfur cluster assembly in Escherichia coli
Abstract
© 2016 John Wiley & Sons, Inc. All rights reserved. Throughout evolution, organisms have adapted a set of dedicated proteins for iron-sulfur cluster biogenesis. Among the identified iron-sulfur cluster assembly proteins in Escherichia coli, IscA has a unique and strong iron-binding activity, and the iron-bound IscA can readily provide iron for iron-sulfur cluster assembly in proteins in vitro under aerobic conditions. IscA also has a high binding affinity for copper, and excess copper competes for the iron-binding sites in IscA and effectively blocks the IscA-mediated iron-sulfur cluster biogenesis. It is thus postulated that IscA may act as an iron chaperone to recruit intracellular iron and deliver iron for iron-sulfur cluster biogenesis under aerobic conditions.