Voltage-dependent gating at the KcsA selectivity filter
- 12 March 2006
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Structural & Molecular Biology
- Vol. 13 (4), 319-322
- https://doi.org/10.1038/nsmb1070
Abstract
The prokaryotic K+ channel KcsA, although lacking a 'standard' voltage-sensing domain, shows voltage-dependent gating that leads to an increase in steady-state open probability of almost two orders of magnitude between +150 and −150 mV. Here we show that voltage-dependent gating in KcsA is associated with the movement of ∼ 0.7 equivalent electronic charges. This charge movement produces an increase in the rate of entry into a long-lived inactivated state and seems to be independent of the proton-activation mechanism. Charge neutralization at position 71 renders the channel essentially voltage-independent by preventing entry into the inactivated state. A mechanism for voltage-dependent gating at the selectivity filter is proposed that is based on the reorientation of the carboxylic moiety of Glu71 and its influence in the conformational dynamics of the selectivity filter.Keywords
This publication has 31 references indexed in Scilit:
- Voltage Sensor of Kv1.2: Structural Basis of Electromechanical CouplingScience, 2005
- Crystal Structure of a Mammalian Voltage-Dependent Shaker Family K + ChannelScience, 2005
- The voltage-sensor structure in a voltage-gated channelTrends in Biochemical Sciences, 2005
- Stirring up controversy with a voltage sensor paddleTrends in Neurosciences, 2004
- X-ray structure of a voltage-dependent K+ channelNature, 2003
- Single Streptomyces lividans K+ ChannelsThe Journal of general physiology, 1999
- Potassium and Sodium Binding to the Outer Mouth of the K+ ChannelBiochemistry, 1999
- The Structure of the Potassium Channel: Molecular Basis of K + Conduction and SelectivityScience, 1998
- Structural Dynamics of the Streptomyces lividans K+ Channel (SKC1): Oligomeric Stoichiometry and Stability,Biochemistry, 1997
- Gating of the voltage-dependent chloride channel CIC-0 by the permeant anionNature, 1995