Conservation of residues in the IQ motif of NaV and CaV channels. NaV and CaV sequence alignments using the sequences (from top to bottom): NaV1.5 (SWISSPROT Q14524), NaV1.1 (P35498), NaV1.2 (Q99250), NaV1.3 (Q9NY46), NaV1.4 (P35499), NaV1.6 (Q9UQD0), NaV1.7 (Q15858), NaV1.8 (Q9Y5Y9), NaV1.9 (Q9UI33), Cav1.1 (Q13698), Cav1.2 (Q13936), CaV2.1 (O00555), and Cav2.2 (Q00975). Residues are colored based on extent of sequence identity. The NaV1.5 IQ motif structure is represented on the top of the alignment. The zigzag line represents α helix, straight lines non-helical regions, and dashed lines residues not present in the IQ motif construct. Stars highlight residues predicted to be important for CaM/NaV1.5 IQ motif interaction. An open circle highlights Ser1904.