Sequence alignment of five mammalian NAT proteins. The primary sequences of human, mouse and Syrian hamster NAT proteins are aligned. Similar amino acids are highlighted by dark grey lettering in pale grey boxes; completely conserved residues are indicated by white lettering on a dark grey background. The residues of the catalytic triad are indicated by a blue arrow. Each residue putatively involved in substrate selectivity is indicated by a star. Alignments were generated using Clustal W  and the figure was prepared using ESPript 2.2 .