title: Crystal structure of mitochondrial quinol-fumarate reductase from the parasitic nematode Ascaris suum.
abstract: In the anaerobic respiratory chain of the parasitic nematode Ascaris suum, complex II couples the reduction of fumarate to the oxidation of rhodoquinol, a reverse reaction catalyzed by mammalian complex II. In this study, the first structure of anaerobic complex II of mitochondria was determined. The structure, composed of four subunits and five co-factors, is similar to that of aerobic complex II, except for an extra peptide found in the smallest anchor subunit of the A. suum enzyme. We discuss herein the structure-function relationship of the enzyme and the critical role of the low redox potential of rhodoquinol in the fumarate reduction of A. suum complex II.
authors.affiliation: Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Hironari
authors.initials: H
authors.lastname: Shimizu
authors.forename: Arihiro
authors.initials: A
authors.lastname: Osanai
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Daniel Ken
authors.initials: DK
authors.lastname: Inaoka
authors.forename: Tomoo
authors.initials: T
authors.lastname: Shiba
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Harada
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000818:Animals; D017165:Ascaris suum / Q000201:enzymology*; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D014451:Ubiquinone; D010088:Oxidoreductases; C424907:quinol fumarate reductase