Fig. 6. The C-termini of KCNQ2 and KCNQ3 contain a potential ankyrin-G-interaction domain. (A) Schematic structure of the KCNQ2 and KCNQ3 subunits with indications of domains of protein-protein interaction. Indicated is also the presence of the ankyrin-G-interaction site in the C-termini of both the KCNQ2 and KCNQ3 subunits. Each circle represents an amino acid. Abbreviations: AKAP, A-kinase anchoring protein, CaM; calmodulin; si, subunit interaction. (B) Clustal W alignment of the 9 amino acid ankyrin-G-binding motif of Nav1.6 along with the ankyrin-G-interaction domain of KCNQ2 and KCNQ3, the corresponding accession no. given in brackets. Red indicates small, hydrophobic residues, blue represents acidic residues, and pink labels basic residues, while green is representative of amino acids containing hydroxyl or amine sidegroups. Asterisks (^*) indicate that the residues in that column are identical in all sequences of the alignment; colons (:) indicate that conserved substitutions have been observed.