Download MendeleyCrystal structure of an inactivated mutant mammalian voltage-gated K(+) channel.
Pau, V., Zhou, Y., Ramu, Y., Xu, Y., Lu, Z.(2017) Nat Struct Mol Biol 24: 857-865
- PubMed: 28846092
- DOI: https://doi.org/10.1038/nsmb.3457
- Primary Citation of Related Structures:
5WIE - PubMed Abstract:
C-type inactivation underlies important roles played by voltage-gated K + (Kv) channels. Functional studies have provided strong evidence that a common underlying cause of this type of inactivation is an alteration near the extracellular end of the channel's ion-selectivity filter. Unlike N-type inactivation, which is known to reflect occlusion of the channel's intracellular end, the structural mechanism of C-type inactivation remains controversial and may have many detailed variations. Here we report that in voltage-gated Shaker K + channels lacking N-type inactivation, a mutation enhancing inactivation disrupts the outermost K + site in the selectivity filter. Furthermore, in a crystal structure of the Kv1.2-2.1 chimeric channel bearing the same mutation, the outermost K + site, which is formed by eight carbonyl-oxygen atoms, appears to be slightly too small to readily accommodate a K + ion and in fact exhibits little ion density; this structural finding is consistent with the functional hallmark of C-type inactivation.
Organizational Affiliation:
Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
