Activities of the Serratia marcescens Heme Receptor HasR and Isolated Plug and -Barrel Domains: the -Barrel Forms a Heme-Specific Channel
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چکیده
Activities of the Serratia marcescens Heme Receptor HasR and Isolated Plug and -Barrel Domains: the -Barrel Forms a Heme-Specific Channel Sylvie Létoffé, Karine Wecker, Muriel Delepierre, Philippe Delepelaire, and Cécile Wandersman* Unité des Membranes Bactériennes, Institut Pasteur, CNRS URA 2172, 25 rue du Dr Roux, 75724 Paris Cedex 15, France, and Unité de Résonance Magnétique Nucléaire des Biomolécules, Institut Pasteur, CNRS URA 2185, 25 rue du Dr Roux, 75724 Paris Cedex 15, France
منابع مشابه
The heme transfer from the soluble HasA hemophore to its membrane-bound receptor HasR is driven by protein-protein interaction from a high to a lower affinity binding site.
HasA is an extracellular heme binding protein, and HasR is an outer membrane receptor protein from Serratia marcescens. They are the initial partners of a heme internalization system allowing S. marcescens to scavenge heme at very low concentrations due to the very high affinity of HasA for heme (Ka = 5,3 x 10(10) m(-1)). Heme is then transferred to HasR, which has a lower affinity for heme. Th...
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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-affin...
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Serratia marcescens hemTUV genes encoding a potential heme permease were cloned in Escherichia coli recombinant mutant FB827 dppF::Km(pAM 238-hasR). This strain, which expresses HasR, a foreign heme outer membrane receptor, is potentially capable of using heme as an iron source. However, this process is invalidated due to a dppF::Km mutation which inactivates the Dpp heme/peptide permease respo...
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Bacterial cells sense the extracellular environment and adapt to that environment by activating gene regulation circuits, often by means of signaling molecules. The Serratia marcescens hemophore is a signaling molecule that acts as an extracellular heme-scavenging protein. The heme-loaded hemophore interacts with its cognate receptor (HasR), triggering transmembrane signaling and turning on tra...
متن کاملFunctional characterization of the HasA(PF) hemophore and its truncated and chimeric variants: determination of a region involved in binding to the hemophore receptor.
Hemophores are secreted by several gram-negative bacteria (Serratia marcescens, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Yersinia pestis) and form a family of homologous proteins. Unlike the S. marcescens hemophore (HasA(SM)), the P. fluorescens hemophore HasA(PF) has an additional region of 12 residues located immediately upstream from the C-terminal secretion signal. We show that ...
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