Structural characterization of the interaction of the delta and alpha subunits of the Escherichia coli F1F0-ATP synthase by NMR spectroscopy

Biochemistry. 2005 Sep 6;44(35):11786-94. doi: 10.1021/bi0510678.

Abstract

A critical point of interaction between F(1) and F(0) in the bacterial F(1)F(0)-ATP synthase is formed by the alpha and delta subunits. Previous work has shown that the N-terminal domain (residues 3-105) of the delta subunit forms a 6 alpha-helix bundle [Wilkens, S., Dunn, S. D., Chandler, J., Dahlquist, F. W., and Capaldi, R. A. (1997) Nat. Struct. Biol. 4, 198-201] and that the majority of the binding energy between delta and F(1) is provided by the interaction between the N-terminal 22 residues of the alpha- and N-terminal domain of the delta subunit [Weber, J., Muharemagic, A., Wilke-Mounts, S., and Senior, A. E. (2003) J. Biol. Chem. 278, 13623-13626]. We have now analyzed a 1:1 complex of the delta-subunit N-terminal domain and a peptide comprising the N-terminal 22 residues of the alpha subunit by heteronuclear protein NMR spectroscopy. A comparison of the chemical-shift values of delta-subunit residues with and without alpha N-terminal peptide bound indicates that the binding interface on the N-terminal domain of the delta subunit is formed by alpha helices I and V. NOE cross-peak patterns in 2D (12)C/(12)C-filtered NOESY spectra of the (13)C-labeled delta-subunit N-terminal domain in complex with unlabeled peptide verify that residues 8-18 in the alpha-subunit N-terminal peptide are folded as an alpha helix when bound to delta N-terminal domain. On the basis of intermolecular contacts observed in (12)C/(13)C-filtered NOESY experiments, we describe structural details of the interaction of the delta-subunit N-terminal domain with the alpha-subunit N-terminal alpha helix.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proton-Translocating ATPases / chemistry*
  • Bacterial Proton-Translocating ATPases / genetics
  • Binding Sites
  • Electron Spin Resonance Spectroscopy
  • Escherichia coli / enzymology
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein Subunits / chemistry*

Substances

  • Protein Subunits
  • Bacterial Proton-Translocating ATPases

Associated data

  • PDB/2A7U