Catalytic mechanisms of complex II enzymes: A structural perspective

Over a decade has passed since the elucidation of the first X-ray crystal structure of any complex II homolog. In the intervening time, the structures of five additional integral-membrane complex II enzymes and three homologs of the soluble domain have been determined. These structures have provided a framework for the analysis of enzymological studies of complex II superfamily enzymes, and have contributed to detailed proposals for reaction mechanisms at each of the two enzyme active sites, which catalyze dicarboxylate and quinone oxidoreduction, respectively. This review focuses on how structural data have augmented our understanding of catalysis by the superfamily. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (235 K)Download as PowerPoint slideHighlights► An overview of the structures of complex II superfamily enzymes is presented. ► The contribution of the structures to the development of reaction mechanisms is reviewed. ► Detailed proposals for the function of specific amino acids are discussed.