2bs2: Difference between revisions
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==Overview== | ==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 .. | 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== | ==About this Structure== | ||
2BS2 is a | 2BS2 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Wolinella_succinogenes Wolinella succinogenes] with NA, FAD, FMR, FES, F3S, SF4, HEM and LMT as [http://en.wikipedia.org/wiki/ligands ligands]. This structure superseeds the now removed PDB entry 1QLA. Active as [http://en.wikipedia.org/wiki/Succinate_dehydrogenase Succinate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.99.1 1.3.99.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BS2 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: tricarboxylic acid cycle]] | [[Category: tricarboxylic acid cycle]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:09:26 2007'' | ||
