Molecular movement of the voltage sensor in a K channel
2003 (English)In: Journal of General Physiology, ISSN 0022-1295 (print), 1540-7748 (online), Vol. 122, no 6, 741-748 p.Article in journal (Refereed) Published
The X-ray crystallographic structure of KvAP, a voltage-gated bacterial K channel, was recently published. However, the position and the molecular movement of the voltage sensor, S4, are still controversial. For example, in the crystallographic structure, S4 is located far away (>30 Å) from the pore domain, whereas electrostatic experiments have suggested that S4 is located close (<8 Å) to the pore domain in open channels. To test the proposed location and motion of S4 relative to the pore domain, we induced disulphide bonds between pairs of introduced cysteines: one in S4 and one in the pore domain. Several residues in S4 formed a state-dependent disulphide bond with a residue in the pore domain. Our data suggest that S4 is located close to the pore domain in a neighboring subunit. Our data also place constraints on possible models for S4 movement and are not compatible with a recently proposed KvAP model.
Place, publisher, year, edition, pages
2003. Vol. 122, no 6, 741-748 p.
Shaker K channel, voltage gated, disulfide, S4 movement, helical screw
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-12994DOI: 10.1085/jgp.200308927OAI: oai:DiVA.org:liu-12994DiVA: diva2:17633