Download MendeleyCharacterization of a Dipartite Iron Uptake System from Uropathogenic Escherichia coli Strain F11.
Koch, D., Chan, A.C., Murphy, M.E., Lilie, H., Grass, G., Nies, D.H.(2011) J Biol Chem 286: 25317-25330
- PubMed: 21596746
- DOI: https://doi.org/10.1074/jbc.M111.222745
- Primary Citation of Related Structures:
3NRP, 3NRQ - PubMed Abstract:
In the uropathogenic Escherichia coli strain F11, in silico genome analysis revealed the dicistronic iron uptake operon fetMP, which is under iron-regulated control mediated by the Fur regulator. The expression of fetMP in a mutant strain lacking known iron uptake systems improved growth under iron depletion and increased cellular iron accumulation. FetM is a member of the iron/lead transporter superfamily and is essential for iron uptake by the Fet system. FetP is a periplasmic protein that enhanced iron uptake by FetM. Recombinant FetP bound Cu(II) and the iron analog Mn(II) at distinct sites. The crystal structure of the FetP dimer reveals a copper site in each FetP subunit that adopts two conformations: CuA with a tetrahedral geometry composed of His(44), Met(90), His(97), and His(127), and CuB, a second degenerate octahedral geometry with the addition of Glu(46). The copper ions of each site occupy distinct positions and are separated by ∼1.3 Å. Nearby, a putative additional Cu(I) binding site is proposed as an electron source that may function with CuA/CuB displacement to reduce Fe(III) for transport by FetM. Together, these data indicate that FetMP is an additional iron uptake system composed of a putative iron permease and an iron-scavenging and potentially iron-reducing periplasmic protein.
Organizational Affiliation:
Molecular Microbiology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120 Halle/Saale, Germany.
