Quinol:fumarate oxidoreductases and succinate:quinone oxidoreductases: phylogenetic relationships, metal centres and membrane attachment

• Published in: BBA - Bioenergetics Vol. 1553; no. 1; pp. 158 - 170
• Main Authors: Lemos, Rita S, Fernandes, Andreia S, Pereira, Manuela M, Gomes, Cláudio M, Teixeira, Miguel
• Format: Book Review Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 17-01-2002
• Subjects: Amino Acid Sequence; Amphipathic helix; Electron Transport Complex II; Flavoproteins - chemistry; Fumarates - chemistry; Heme - chemistry; Iron-Sulfur Proteins - chemistry; Metals - chemistry; Models, Molecular; Molecular Sequence Data; Multienzyme Complexes - chemistry; Multienzyme Complexes - classification; Multienzyme Complexes - genetics; Oxidation-Reduction; Oxidoreductases - chemistry; Oxidoreductases - classification; Oxidoreductases - genetics; Phylogeny; Quinol:fumarate oxidoreductase; Quinone Reductases - chemistry; Quinone Reductases - classification; Quinone Reductases - genetics; Redox-Bohr; Sequence Alignment; Sequence Homology, Amino Acid; Succinate Dehydrogenase - chemistry; Succinate Dehydrogenase - classification; Succinate Dehydrogenase - genetics; Succinate:quinone oxidoreductase; Succinic Acid - chemistry; Phylogeny; Redox-Bohr; Succinate:quinone oxidoreductase; Quinol:fumarate oxidoreductase; Amphipathic helix
• ISSN: 0005-2728; 0006-3002; 1879-2650
• DOI: 10.1016/S0005-2728(01)00239-0

A comprehensive phylogenetic analysis of the core subunits of succinate:quinone oxidoreductases and quinol:fumarate oxidoreductases is performed, showing that the classification of the enzymes as type A to E based on the type of the membrane anchor fully correlates with the specific characteristics of the two core subunits. A special emphasis is given to the type E enzymes, which have an atypical association to the membrane, possibly involving anchor subunits with amphipathic helices. Furthermore, the redox properties of the SQR/QFR proteins are also reviewed, stressing out the recent observation of redox-Bohr effect upon haem reduction, observed for the
Desulfovibrio gigas and
Rhodothermus marinus enzymes, which indicates a direct protonation event at the haems or at a nearby residue. Finally, the possible contribution of these enzymes to the formation/dissipation of a transmembrane proton gradient is discussed, considering recent experimental and structural data.