Fig. 2. Sequence comparison of DSPS2 and the known homologs. Alignment showing the Drosophila (Dm SPS2), human (Hs SPS2), mouse (Mo SPS2), M. jannaschii (Mj SPS), and E. coli (Ec SelD) SPS proteins and Drosophila SelD like protein (Dm SelD like). Position corresponding to Cys-17 of E. coli SelD is indicated by an asterisk, X denotes the Sec residue. Boxes: catalytic center (Motif A) and the ATP/GTP binding site (Motif B).