Figure 2.

(Left) Quantitative analysis of homologies between protein sequences in GenBank (May 1997 release) and human peropsin, bovine RGR, and squid retinochrome as determined by the blast algorithm (27). The P value is the probability of finding a comparable match by chance in a random sequence database of equivalent size. Horizontal bars indicate the range of P values for the indicated classes of sequences. Redundant database entries have not been eliminated for this analysis. (Right) Dendrogram of visual pigments and visual pigment-related proteins calculated using geneworks software with gap penalties set at 5 for each gap and 25 for lengthening a gap. In the dendrogram, the length of each line is proportional to the degree of amino acid sequence divergence. The rat 5HT-7 and human alpha 1B adrenergic receptors are two of the five nonvisual pigment G protein-coupled receptors in the GenBank database that are most homologous to peropsin.