A putative prokaryote voltage-gated Ca(2+) channel with only one 6TM motif per subunit

Biochem Biophys Res Commun. 2001 Mar 2;281(3):741-6. doi: 10.1006/bbrc.2001.4408.


Until now, voltage-gated Ca(2+) channel proteins have been found only in eukaryotes. Here we report that a gene recently discovered in the eubacterium Bacillus halodurans codes for a protein closely related to eukaryotic Ca(2+) channels, but that has only one 6-transmembrane-segement (6TM) motif, instead of four, in its pore-forming subunit. This is supported by the comparison of consensus sequences, which, along with the patterns of residue conservation, indicates a similar structure in the membrane to voltage-gated K(+) channels. From this we hypothesize that Ca(2+) channels originally evolved in bacteria, and that the specific eubacteria protein highlighted here is an ideal candidate for structure determination efforts.

MeSH terms

  • Amino Acid Sequence
  • Calcium Channels / chemistry*
  • Ion Channel Gating*
  • Molecular Sequence Data
  • Protein Conformation
  • Sequence Homology, Amino Acid


  • Calcium Channels