title: Exploring the molecular nature of alternative oxidase regulation and catalysis.
abstract: Plant mitochondria contain a non-protonmotive alternative oxidase (AOX) that couples the oxidation of ubiquinol to the complete reduction of oxygen to water. In this paper we review theoretical and experimental studies that have contributed to our current structural and mechanistic understanding of the oxidase and to the clarification of the molecular nature of post-translational regulatory phenomena. Furthermore, we suggest a catalytic cycle for AOX that involves at least one transient protein-derived radical. The model is based on the reviewed information and on recent insights into the mechanisms of cytochrome c oxidase and the hydroxylase component of methane monooxygenase.
authors.affiliation: Department of Biochemistry, University of Sussex, Falmer, Brighton BN1 9QG, UK. c.affourtit@sussex.ac.uk
authors.forename: Charles
authors.initials: C
authors.lastname: Affourtit
authors.forename: Mary S
authors.initials: MS
authors.lastname: Albury
authors.forename: Paul G
authors.initials: PG
authors.lastname: Crichton
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Moore
mesh_terms: D002384:Catalysis; D003576:Electron Transport Complex IV / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D000099188:Alternative Oxidase
chemical_list: D003576:Electron Transport Complex IV; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010105:Oxygenases; D010940:Plant Proteins; D000099188:Alternative Oxidase; C021555:methane monooxygenase