Fig. 1. Evolutionary conservation of KAL proteins. (A) Amino acid sequence alignment of known KAL homologs. KAL, human KAL protein; KALc, chicken KAL protein; zKAL1.1 and zKAL1.2, zebrafish KAL proteins (Ardouin et al., 2000); and CeKAL, C. elegans KAL protein. Stars highlight conserved cysteines. The WAP domain is underlined. In the most conserved part of the protein, containing the cysteine-rich region, the WAP domain and the first FNIII repeat, identity and similarity of residues between KAL and CeKAL are approximately 30% and 50%, respectively. (B) The domain topology of KAL proteins. The order and the relative distance of all domains are conserved. Abbreviations: SP, signal peptide; C-rich, cysteine-rich domain; WAP, WAP domain; FNIII, fibronectin type III repeat; GPI, glycosyl-phosphatidyl-inositol anchoring site.