Multiple sequence alignment of subgroup 1 human BTB/kelch proteins. The kelch-repeat domains of the 15 subgroup 1 BTB/kelch proteins were aligned in CLUSTALW to generate a 50 % identity threshold level consensus sequence. The alignments are presented for each repeat, with the repeat unit assigned according to the 1GOF structure. The four β-strands in each repeat are color-coded as in Fig. 1A. Alignments are presented in Boxshade: black shading indicates identical amino acids, grey shading indicates similar amino acids and white background indicates unrelated amino acids.