Atomic distance estimates from disulfides and high-affinity metal-binding sites in a K+ channel pore.
Journal Article (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
Pubmed Central ID
- PMC1184301
International Standard Serial Number (ISSN)
- 0006-3495
Digital Object Identifier (DOI)
- 10.1016/S0006-3495(97)78651-X
Language
- eng
Conference Location
- United States