title: Review and Hypothesis. New insights into the reaction mechanism of transhydrogenase: Swivelling the dIII component may gate the proton channel.
abstract: The membrane protein transhydrogenase in animal mitochondria and bacteria couples reduction of NADP⁺ by NADH to proton translocation. Recent X-ray data on Thermus thermophilus transhydrogenase indicate a significant difference in the orientations of the two dIII components of the enzyme dimer (Leung et al., 2015). The character of the orientation change, and a review of information on the kinetics and thermodynamics of transhydrogenase, indicate that dIII swivelling might assist in the control of proton gating by the redox state of bound NADP⁺/NADPH during enzyme turnover.
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK. Electronic address: j.b.jackson@bham.ac.uk.
authors.forename: J Baz
authors.initials: JB
authors.lastname: Jackson
authors.affiliation: Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92307, USA.
authors.forename: Josephine H
authors.initials: JH
authors.lastname: Leung
authors.affiliation: Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92307, USA.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Stout
authors.affiliation: Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Lici A
authors.initials: LA
authors.lastname: Schurig-Briccio
authors.affiliation: Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gennis
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D006801:Humans; D051336:Mitochondrial Membranes / Q000201:enzymology*; D008958:Models, Molecular; D009154:Mutation; D009250:NADP Transhydrogenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D021122:Protein Subunits
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D009250:NADP Transhydrogenases
keywords: Membrane-protein structure; Nicotinamide nucleotide; Proton-gating; Proton-pump; Transhydrogenase