Segment TM7 from the cytoplasmic hemi-channel from Vo-H+-V-ATPase includes a flexible region that has a potential role in proton translocation

A.M. Duarte, E.R. de Jong, R. Wechselberger, C.P.M. van Mierlo, M.A. Hemminga

Research output: Contribution to journalArticleAcademicpeer-review

13 Citations (Scopus)

Abstract

A 900-MHz NMR study is reported of peptide sMTM7 that mimics the cytoplasmic proton hemi-channel domain of the seventh transmembrane segment (TM7) from subunit a of H+-V-ATPase from Saccharomyces cerevisiae. The peptide encompasses the amino acid residues known to actively participate in proton translocation. In addition, peptide sMTM7 contains the amino acid residues that upon mutation cause V-ATPase to become resistant against the inhibitor bafilomycin. 2D TOCSY and NOESY 1H¿1H NMR spectra are obtained of sMTM7 dissolved in d6-DMSO and are used to calculate the three-dimensional structure of the peptide. The NMR-based structures and corresponding dynamical features of peptide sMTM7 show that sMTM7 is composed of two ¿-helical regions. These regions are separated by a flexible hinge of two residues. The hinge acts as a ball-and-joint socket and both helical segments move independently with respect to one another. This movement in TM7 is suggested to cause the opening and closing of the cytoplasmic proton hemi-channel and enables proton translocation.
Original languageEnglish
Pages (from-to)2263-2270
JournalBiochimica et Biophysica Acta. Biomembranes
Volume1768
Issue number9
DOIs
Publication statusPublished - 2007

Keywords

  • mediated cross-linking
  • transmembrane segment
  • chemical-shifts
  • subunit
  • nmr
  • peptide
  • binding
  • system
  • pumps

Fingerprint Dive into the research topics of 'Segment TM7 from the cytoplasmic hemi-channel from Vo-H+-V-ATPase includes a flexible region that has a potential role in proton translocation'. Together they form a unique fingerprint.

Cite this