FIG. 2.
Alignment of the sequences from the C4-dicarboxylate and tricarboxylate binding sites in DcuS and CitA proteins. The sequences are limited to residues 90 to 170 of DcuS from E. coli. These represent the major part of the periplasmic domain (amino acids 42 to 181) and the corresponding sequences from the homologous proteins. Residues in the part of the pocket close to the exit in DcuS and CitA are shown in green, those from the buried part of the pocket in red, and those located in between in magenta. Conserved and essential residues of DcuS and CitA and the ligands of citrate in CitA are highlighted. The subtype-specific residues are indicated by arrows. EC, E. coli; BS, Bacillus subtilis; BH, Bacillus halodurans; KP, K. pneumoniae.