Title: A prokaryotic voltage-gated sodium channel.

Authors: D Ren, B Navarro, H Xu, L Yue, Q Shi, D E Clapham

Journal, date & volume: Science, 2001 Dec 14 , 294, 2372-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11743207

Abstract
The pore-forming subunits of canonical voltage-gated sodium and calcium channels are encoded by four repeated domains of six-transmembrane (6TM) segments. We expressed and characterized a bacterial ion channel (NaChBac) from Bacillus halodurans that is encoded by one 6TM segment. The sequence, especially in the pore region, is similar to that of voltage-gated calcium channels. The expressed channel was activated by voltage and was blocked by calcium channel blockers. However, the channel was selective for sodium. The identification of NaChBac as a functionally expressed bacterial voltage-sensitive ion-selective channel provides insight into both voltage-dependent activation and divalent cation selectivity.