On the structural basis of modal gating behavior in K(+) channels

Nat Struct Mol Biol. 2011 Jan;18(1):67-74. doi: 10.1038/nsmb.1968. Epub 2010 Dec 26.


Modal-gating shifts represent an effective regulatory mechanism by which ion channels control the extent and time course of ionic fluxes. Under steady-state conditions, the K(+) channel KcsA shows three distinct gating modes, high-P(o), low-P(o) and a high-frequency flicker mode, each with about an order of magnitude difference in their mean open times. Here we show that in the absence of C-type inactivation, mutations at the pore-helix position Glu71 unmask a series of kinetically distinct modes of gating in a side chain-specific way. These gating modes mirror those seen in wild-type channels and suggest that specific interactions in the side chain network surrounding the selectivity filter, in concert with ion occupancy, alter the relative stability of pre-existing conformational states of the pore. The present results highlight the key role of the selectivity filter in regulating modal gating behavior in K(+) channels.

Publication types

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

MeSH terms

  • Amino Acid Substitution
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / physiology
  • Crystallography, X-Ray
  • Ion Channel Gating*
  • Kinetics
  • Models, Molecular
  • Mutation
  • Potassium Channels / chemistry*
  • Potassium Channels / physiology
  • Protein Structure, Tertiary
  • Sequence Analysis, Protein


  • Bacterial Proteins
  • Potassium Channels
  • prokaryotic potassium channel

Associated data

  • PDB/3OR6
  • PDB/3OR7