Fig. 1.

CG1753 is the D. melanogaster CBS. (A) Schematic representation of the TSP and associated relationships. Components of the TSP are shown within the gray box. (B) Multiple sequence alignment of human, mouse, and fly CBS proteins shows a high degree of evolutionary conservation. Three regions containing important domains in human CBS are indicated by underlining: the heme binding domain (40% sequence identity; red), a catalytic domain (64% sequence identity; green), and two CBS domains (28% sequence identity; brown).