Structure of the KvAP voltage-dependent K+ channel and its dependence on the lipid membrane.

Journal Article (Journal Article)

Voltage-dependent ion channels gate open in response to changes in cell membrane voltage. This form of gating permits the propagation of action potentials. We present two structures of the voltage-dependent K(+) channel KvAP, in complex with monoclonal Fv fragments (3.9 A) and without antibody fragments (8 A). We also studied KvAP with disulfide cross-bridges in lipid membranes. Analyzing these data in the context of the crystal structure of Kv1.2 and EPR data on KvAP we reach the following conclusions: (i) KvAP is similar in structure to Kv1.2 with a very modest difference in the orientation of its voltage sensor; (ii) mAb fragments are not the source of non-native conformations of KvAP in crystal structures; (iii) because KvAP contains separate loosely adherent domains, a lipid membrane is required to maintain their correct relative orientations, and (iv) the model of KvAP is consistent with the proposal of voltage sensing through the movement of an arginine-containing helix-turn-helix element at the protein-lipid interface.

Full Text

Duke Authors

Cited Authors

  • Lee, S-Y; Lee, A; Chen, J; MacKinnon, R

Published Date

  • October 25, 2005

Published In

Volume / Issue

  • 102 / 43

Start / End Page

  • 15441 - 15446

PubMed ID

  • 16223877

Pubmed Central ID

  • PMC1253646

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.0507651102

Language

  • eng

Conference Location

  • United States