Download MendeleyOn the structural basis of modal gating behavior in K(+) channels.
Chakrapani, S., Cordero-Morales, J.F., Jogini, V., Pan, A.C., Cortes, D.M., Roux, B., Perozo, E.(2011) Nat Struct Mol Biol 18: 67-74
- PubMed: 21186363
- DOI: https://doi.org/10.1038/nsmb.1968
- Primary Citation of Related Structures:
3OR6, 3OR7 - PubMed Abstract:
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.
Organizational Affiliation:
Department of Biochemistry and Molecular Biology, University of Chicago, Center for Integrative Science, Chicago, Illinois, USA.
