Conformational changes in the C terminus of Shaker K+ channel bound to the rat Kvbeta2-subunit

Proc Natl Acad Sci U S A. 2003 Oct 28;100(22):12607-12. doi: 10.1073/pnas.2235650100. Epub 2003 Oct 20.

Abstract

We studied the structure of the C terminus of the Shaker potassium channel. The 3D structures of the full-length and a C-terminal deletion (Delta C) mutant of Shaker were determined by electron microscopy and single-particle analysis. The difference map between the full-length and the truncated channels clearly shows a compact density, located on the sides of the T1 domain, that corresponds to a large part of the C terminus. We also expressed and purified both WT and Delta C Shaker, assembled with the rat KvBeta2-subunit. By using a difference map between the full-length and truncated Shaker alpha-beta complexes, a conformational change was identified that shifts a large part of the C terminus away from the membrane domain and into close contact with the Beta-subunit. This conformational change, induced by the binding of the KvBeta2-subunit, suggests a possible mechanism for the modulation of the K+ voltage-gated channel function by its Beta-subunit.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • COS Cells
  • Chlorocebus aethiops
  • Fourier Analysis
  • Models, Molecular
  • Peptide Fragments / chemistry
  • Potassium Channels / chemistry*
  • Potassium Channels / genetics
  • Potassium Channels, Voltage-Gated*
  • Protein Conformation*
  • Protein Subunits / chemistry
  • Rats
  • Recombinant Proteins / chemistry
  • Restriction Mapping
  • Shaker Superfamily of Potassium Channels
  • Transfection

Substances

  • Kcnab2 protein, rat
  • Peptide Fragments
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • Protein Subunits
  • Recombinant Proteins
  • Shaker Superfamily of Potassium Channels