The Enigma family of PDZ-LIM proteins. (A) Enigma, ENH, RIL, CLP36, and ALP have conserved PDZ and LIM domains and represent a family of PDZ–LIM proteins. Percentages of amino acid identities between LIM and PDZ domains of family members are indicated. (B) Amino acid sequence alignment of PDZ domains of Enigma, ENH, RIL, CLP36, ALP, Dlg (PDZs 1 and 2), and LIM kinase. Four residues that reside in the carboxylate-binding loop of PDZ domains, the Gly-Leu-Gly-Phe sequence for which PDZ domains were originally named, are boxed. Among Enigma family members the sequence (Pro/Ser)-Trp-Gly-Phe occurs at this site. A histidine residue that is conserved in the Enigma family (His-63 in Enigma) is indicated with an asterisk. Amino acid identities among Enigma family and other PDZ domains are indicated by shading. The amino acid sequences used in this study were obtained from the following database entries: Enigma, L35240; ENH, U48247; RIL, X76454; CLP36, U23769; Dlg, M73529; LIM kinase, D26309; and ALP (Xia et al., 1997).