Two-dimensional crystallization and projection structure of KcsA potassium channel.

Journal Article (Journal Article)

Potassium channels are integral membrane proteins that play a crucial role in regulating diverse cell functions in both electrically excitable and non-excitable cells. Molecular cloning has revealed a diverse family of genes that encode these proteins, and a variety of experimental strategies have defined functional domains. We have cloned, over-expressed and purified the KcsA potassium channel to homogeneity and reconstituted this channel protein with phospholipids to form two-dimensional crystals. The crystals belong to plane group p4 and have unit cell dimensions of a=b=48 A. A projection map at 6 A resolution has been obtained by electron crystallography. The map shows that the protein is a homotetramer, having a low-density region on the 4-fold axis that is the site of the ion conduction pathway. Each monomer contains density features that are consistent with the molecular model of a truncated form of KcsA recently determined by X-ray crystallography.

Full Text

Duke Authors

Cited Authors

  • Li, HL; Sui, HX; Ghanshani, S; Lee, S; Walian, PJ; Wu, CL; Chandy, KG; Jap, BK

Published Date

  • September 18, 1998

Published In

Volume / Issue

  • 282 / 2

Start / End Page

  • 211 - 216

PubMed ID

  • 9735281

International Standard Serial Number (ISSN)

  • 0022-2836

Digital Object Identifier (DOI)

  • 10.1006/jmbi.1998.2016


  • eng

Conference Location

  • Netherlands