Heme uptake across the outer membrane as revealed by crystal structures of the receptor-hemophore complex
Heme uptake across the outer membrane as revealed by crystal structures of the receptor-hemophore complex
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DOI：
10.1073/pnas.0809406106
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发表时间：
2009-01-27
影响因子：
11.1
通讯作者：
Welte, Wolfram
中科院分区：
文献类型：
--
作者：
Krieg, Stefanie;Huche, Frederic;Welte, Wolfram
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 angstrom 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
