Review and Hypothesis. New insights into the reaction mechanism of transhydrogenase: Swivelling the dIII component may gate the proton channel

FEBS Lett. 2015 Jul 22;589(16):2027-33. doi: 10.1016/j.febslet.2015.06.027. Epub 2015 Jul 2.

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.

Keywords: Membrane-protein structure; Nicotinamide nucleotide; Proton-gating; Proton-pump; Transhydrogenase.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Biocatalysis
  • Humans
  • Mitochondrial Membranes / enzymology*
  • Models, Molecular*
  • Mutation
  • NADP Transhydrogenases / chemistry*
  • NADP Transhydrogenases / genetics
  • NADP Transhydrogenases / metabolism*
  • Protein Conformation
  • Protein Subunits

Substances

  • Bacterial Proteins
  • Protein Subunits
  • NADP Transhydrogenases