3NRP

Crystal structure of 'as isolated' uropathogenic E. coli strain F11 FetP recombinantly expressed in the periplasm of E. coli BL21(DE3)

Summary for 3NRP

• Entry DOI: 10.2210/pdb3nrp/pdb
• Related: 3NRQ
• Descriptor: Periplasmic protein-probably involved in high-affinity Fe2+ transport (2 entities in total)
• Functional Keywords: immunoglobulin-like fold, iron transporter, copper binding, transport protein
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 70643.78

Authors

Chan, A.C.K.,Murphy, M.E.P. (deposition date: 2010-06-30, release date: 2011-05-18, Last modification date: 2023-12-27)

Primary citation

Koch, D.,Chan, A.C.,Murphy, M.E.,Lilie, H.,Grass, G.,Nies, D.H.
Characterization of a Dipartite Iron Uptake System from Uropathogenic Escherichia coli Strain F11.
J.Biol.Chem., 286:25317-25330, 2011

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.

PubMed: 21596746
DOI: 10.1074/jbc.M111.222745

Experimental method

X-RAY DIFFRACTION (1.6 Å)