Atomic distance estimates from disulfides and high-affinity metal-binding sites in a K+ channel pore.

Journal Article

The pore of potassium channels is lined by four identical, highly conserved hairpin loops, symmetrically arranged around a central permeation pathway. Introduction of cysteines into the external mouth of the drk1 K channel pore resulted in the formation of disulfide bonds that were incompatible with channel function. Breaking these bonds restored function and resulted in a high-affinity Cd(2+)-binding site, indicating coordinated ligation by multiple sulfhydryls. Dimeric constructs showed that these disulfide bonds formed between subunits. These results impose narrow constraints on intersubunit atomic distances in the pore that strongly support a radial pore model. The data also suggest an important functional role for the outer mouth of the pore in gating or permeation.

Full Text

Duke Authors

Cited Authors

  • Krovetz, HS; VanDongen, HM; VanDongen, AM

Published Date

  • January 1997

Published In

Volume / Issue

  • 72 / 1

Start / End Page

  • 117 - 126

PubMed ID

  • 8994597

International Standard Serial Number (ISSN)

  • 0006-3495

Digital Object Identifier (DOI)

  • 10.1016/S0006-3495(97)78651-X

Language

  • eng

Conference Location

  • United States