1kmo

Publication Abstract from PubMed

Siderophore-mediated acquisition systems facilitate iron uptake. We present the crystallographic structure of the integral outer membrane receptor FecA from Escherichia coli with and without ferric citrate at 2.5 and 2.0 angstrom resolution. FecA is composed of three distinct domains: the barrel, plug, and NH2-terminal extension. Binding of ferric citrate triggers a conformational change of the extracellular loops that close the external pocket of FecA. Ligand-induced allosteric transitions are propagated through the outer membrane by the plug domain, signaling the occupancy of the receptor in the periplasm. These data establish the structural basis of gating for receptors dependent on the cytoplasmic membrane protein TonB. By compiling available data for this family of receptors, we propose a mechanism for the energy-dependent transport of siderophores.

Structural basis of gating by the outer membrane transporter FecA.,Ferguson AD, Chakraborty R, Smith BS, Esser L, van der Helm D, Deisenhofer J Science. 2002 Mar 1;295(5560):1715-9. PMID:11872840^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.