Pairwise sequence and structure comparisons of BTB structures. Cells contain the percentage identity and root mean square deviation (Å) value for each structure pair. Representative structures from the Protein Data Bank are labeled as follows: a1buo:A and 1cs3:A; b1nex:a; c1ldk:D, 1p22:b, 1fqv:B, 1fs1:B, 1fs2:B; d1hv2:a; e1vcb:B, 1lm8:C, 1lqb:B; f1a68:_, 1eod:A, 1eoe:A, 1eof:A, 1t1d:A, 1exb:E (rat Kv1.1); g1s1g:A; h1r28:A, 1r29:A, 1r2b:A. The T1 domains from Kv1.2, Kv3.1 and Kv4.2 were omitted for clarity. El.C, ElonginC. Ac, Aplysia californica; Hs, Homo sapiens; Sc, Saccharomyces cerevisiae.