Figure 5. Pore regions and selectivity motifs of animal and diatom voltage activated Na⁺ and Ca²⁺ channels.

ClustalW was used to perform multiple sequence alignment of the 4 ‘P’ loop domains of animal and diatom voltage activated Na⁺/Ca²⁺ channels. The selectivity motifs for each pore domain are indicated by boxes with conserved residues conferring selectivity indicated by asterisk. All 4 residues that contribute to the selectivity filter are indicated [34]. Protein sequences were obtained from NCBI and accession numbers are indicated. The diatom sequence for the putative 4 domain voltage activated Na⁺ permeable channel was obtained through a BLAST search of the Thalassioira pseudonana genome, Protein ID 2207, http://genome.jgi-psf.org/Thaps3/Thaps3.home.html.