Fig.1.

Primary structure of CaBPs and phylogenetic tree. A, sequence alignment of h-CaBP1, h-CaBP2, h-CaBP3, h-CaBP4, h-CaBP5, and h-CaM. Alignment of the deduced aa sequences of h-CaBPs with CaM. The identical residues in all sequences are shown in white letters on black background. The conservative substitutions (E=D; S=T; V=M=I=L; K=R) are shown in white letters on dark gray background. The residues that are identical among CaBPs are shaded in light gray. Functional EF-hand motifs are shown in shaded boxes, and the nonfunctional EF-hand motif is in an open box. Theasterisk represents the myristoylation site, and the down arrowhead over a solid bar indicates a 4-amino acid-long extension of the central a-helix. Arrows indicate the intron/exon junctions for the h-CaBP1, 2, 4, 5, and CaM genes. Vertical bars indicate the intron/exon junctions in CaBP3 and in alternative splice forms of CaBP1 and CaBP2. L- indicates the long spliced forms of CaBPs, and the underlined aa residues are absent in the short spliced forms. The letters h and s above the sequences indicate α-helices and β-strands, respectively. B, phylogenetic tree. The tree was built with a bootstrap analysis of neighbor-joining distance using PAUPSearch in GCG (Genetics Computer Group). The sequences included, with their GenBank™/EMBL accession numbers in parentheses, are: h-CaM (A31920); h-CaM-like protein (P27482); rat caldendrin (Y17048); human recoverin (S62028); GCAP1 (L36859); GCAP2 (see Ref. 30); GCAP3 (AF110002); chicken visinin (P22728); bovine neurocalcin (JH0616); VILIP1: human visinin-like protein 1 (U14747); VILIP2: rat visinin-like protein 2 (P35332); VILIP3: human visinin-like protein 3 (P37235); NCS1: rat neuronal Ca²⁺ sensor 1 (P36610); CaBP4 (unpublished sequence); CaBP1, CaBP2, CaBP3, and CaBP5 are novel sequences reported in this study.