RRC ID 35225
Author Krieg S, Huché F, Diederichs K, Izadi-Pruneyre N, Lecroisey A, Wandersman C, Delepelaire P, Welte W.
Title Heme uptake across the outer membrane as revealed by crystal structures of the receptor-hemophore complex.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract Gram-negative bacteria use specific heme uptake systems, relying on outer membrane receptors and excreted heme-binding proteins (hemophores) to scavenge and actively transport heme. To unravel the unknown molecular details involved, we present 3 structures of the Serratia marcescens receptor HasR in complex with its hemophore HasA. The transfer of heme over a distance of 9 A from its high-affinity site in HasA into a site of lower affinity in HasR is coupled with the exergonic complex formation of the 2 proteins. Upon docking to the receptor, 1 of the 2 axial heme coordinations of the hemophore is initially broken, but the position and orientation of the heme is preserved. Subsequently, steric displacement of heme by a receptor residue ruptures the other axial coordination, leading to heme transfer into the receptor.
Volume 106(4)
Pages 1045-50
Published 2009-1-27
DOI 10.1073/pnas.0809406106
PII 0809406106
PMID 19144921
PMC PMC2633585
MeSH Apoproteins / chemistry Apoproteins / metabolism Bacterial Proteins / chemistry* Bacterial Proteins / metabolism Biological Transport Calorimetry Carrier Proteins / chemistry* Carrier Proteins / metabolism Cell Membrane / metabolism* Crystallography, X-Ray Heme / chemistry Heme / metabolism* Hemeproteins / chemistry* Hemeproteins / metabolism Ligands Membrane Proteins / chemistry* Membrane Proteins / metabolism Models, Molecular Protein Structure, Secondary Receptors, Cell Surface / chemistry* Receptors, Cell Surface / metabolism Serratia marcescens / chemistry* Surface Properties
IF 9.504
Times Cited 91
Prokaryotes E. coli ?