2bs2 | pdb_00002bs2

File:2bs2.gif

QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES

Overview

Membrane protein complexes can support both the generation and utilisation of a transmembrane electrochemical proton potential ('proton-motive force'), either by transmembrane electron transfer coupled to protolytic reactions on opposite sides of the membrane or by transmembrane proton transfer. Here we provide the first evidence that both of these mechanisms are combined in the case of a specific respiratory membrane protein complex, the dihaem-containing quinol:fumarate reductase (QFR) of Wolinella succinogenes, so as to facilitate transmembrane electron transfer by transmembrane proton transfer. We also demonstrate the non-functionality of this novel transmembrane proton transfer pathway ('E-pathway') in a variant QFR where a key glutamate residue has been replaced. The 'E-pathway', discussed on the basis of the 1.78-Angstrom-resolution crystal structure of QFR, can be concluded to be essential also for the viability of pathogenic varepsilon-proteobacteria such as Helicobacter pylori and is possibly relevant to proton transfer in other dihaem-containing membrane proteins, performing very different physiological functions.

About this Structure

2BS2 is a Protein complex structure of sequences from Wolinella succinogenes. This structure supersedes the now removed PDB entry 1qla. Full crystallographic information is available from OCA.

Reference

Evidence for transmembrane proton transfer in a dihaem-containing membrane protein complex., Madej MG, Nasiri HR, Hilgendorff NS, Schwalbe H, Lancaster CR, EMBO J. 2006 Oct 18;25(20):4963-70. Epub 2006 Oct 5. PMID:17024183 Page seeded by OCA on Sat May 3 20:43:10 2008

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