Molecular template for a voltage sensor in a novel K+ channel. III. Functional reconstitution of a sensorless pore module from a prokaryotic Kv channel.

ABSTRACT: KvLm is a prokaryotic voltage-gated K(+) (Kv) channel from Listeria monocytogenes. The sequence of the voltage-sensing module (transmembrane segments S1-S4) of KvLm is atypical in that it contains only three of the eight conserved charged residues known to be deterministic for voltage sensing in eukaryotic Kv's. In contrast, the pore module (PM), including the S4-S5 linker and cytoplasmic tail (linker-S5-P-S6-C-terminus) of KvLm, is highly conserved. Here, the full-length (FL)-KvLm and the KvLm-PM only proteins were expressed, purified, and reconstituted into giant liposomes. The properties of the reconstituted FL-KvLm mirror well the characteristics of the heterologously expressed channel in Escherichia coli spheroplasts: a right-shifted voltage of activation, micromolar tetrabutylammoniu

SUBMITTER: Santos JS 

PROVIDER: S-EPMC2585861 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature