Succinate:quinone oxidoreductases – what can we learn from Wolinella succinogenes quinol:fumarate reductase?

FEBS Letters

Lancaster, C.Roy D¹ 

[1] Max-Planck-Institut für Biophysik, Abteilung Molekulare Membranbiologie, Heinrich-Hoffmann-Str. 7, D-60528 Frankfurt am Main, Germany

关键词: Atomic model;    Bioenergetics;    Fumarate reductase;    Membrane protein;    Succinate dehydrogenase;    X-ray crystallography;   

DOI  :  10.1016/S0014-5793(01)02706-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The structure of Wolinella succinogenes quinol:fumarate reductase by X-ray crystallography has been determined at 2.2-Å resolution [Lancaster et al. (1999), Nature 402, 377–385]. Based on the structure of the three protein subunits A, B, and C and the arrangement of the six prosthetic groups (a covalently bound FAD, three iron–sulphur clusters, and two haem b groups) a pathway of electron transfer from the quinol-oxidising dihaem cytochrome b in the membrane to the site of fumarate reduction in the hydrophilic subunit A has been proposed. By combining the results from site-directed mutagenesis, functional and electrochemical characterisation, and X-ray crystallography, a residue was identified which is essential for menaquinol oxidation. [Lancaster et al. (2000), Proc. Natl. Acad. Sci. USA 97, 13051–13056]. The location of this residue in the structure suggests that the coupling of the oxidation of menaquinol to the reduction of fumarate in dihaem-containing succinate:quinone oxidoreductases could be associated with the generation of a transmembrane electrochemical potential. Based on crystallographic analysis of three different crystal forms of the enzyme and the results from site-directed mutagenesis, we have derived a mechanism of fumarate reduction and succinate oxidation [Lancaster et al. (2001) Eur. J. Biochem. 268, 1820–1827], which should be generally relevant throughout the superfamily of succinate:quinone oxidoreductases.

【 授权许可】

Unknown