Figure 1.

Multiple sequence alignments of voltage sensor domains (VSDs) (S1–S4) from a sample of voltage-gated ion channel (VGIC) alpha subunit domains. Prokaryotic sodium channels are Na_VAb from Arcobacter butzleri (Payandeh et al., 2011), and the NaChBac orthologue Na_VRh from alpha proteobacterium (Zhang et al., 2012). The remaining sequences are human. For each alignment, putative consensus negative charge regions are highlighted with boxes colored according to frequently observed residues (glutamate, yellow; asparagine, red; aspartate, blue). The first five positively charged residues in S4 are shown in green.