3CSL

Structure of the Serratia marcescens hemophore receptor HasR in complex with its hemophore HasA and heme

Summary for 3CSL

• Entry DOI: 10.2210/pdb3csl/pdb
• Related: 3CSN
• Descriptor: HasR protein, Hemophore HasA, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: outer membrane protein, beta-barrel, hemophore receptor, tonb box, heme, iron, metal-binding, secreted, membrane protein-heme binding protein complex, membrane protein/heme binding protein
• Biological source: Serratia marcescens; More
• Cellular location: Cell outer membrane (By similarity): Q79AD2; Secreted: Q54450
• Total number of polymer chains: 4
• Total formula weight: 234833.53

Authors

Krieg, S.,Diederichs, K. (deposition date: 2008-04-10, release date: 2009-01-20, Last modification date: 2024-10-16)

Primary citation

Krieg, S.,Huche, F.,Diederichs, K.,Izadi-Pruneyre, N.,Lecroisey, A.,Wandersman, C.,Delepelaire, P.,Welte, W.
Heme uptake across the outer membrane as revealed by crystal structures of the receptor-hemophore complex.
Proc.Natl.Acad.Sci.USA, 106:1045-1050, 2009

PubMed 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.

PubMed: 19144921
DOI: 10.1073/pnas.0809406106

Experimental method

X-RAY DIFFRACTION (2.7 Å)