Figure 6

Superposition of the conserved active site residues of the 66.3 kDa protein and the four most related N-terminal nucleophile hydrolases. The conserved N-terminal nucleophile is shown completely, while of the ubiquitous asparagine and arginine residues as well as of the residue in the lower right corner only the side chains are represented, since the main chain atoms are not directly involved in catalysis. In contrast, of the other three residues, only the main chain atoms are depicted due to their participation in the catalytic reaction and a lack of sequence conservation. The residues are coloured by atom. Nitrogen, oxygen and sulphur atoms are shown in blue, red and light orange, respectively, for all structures, whereas the carbon atoms are represented distinctly for the various structures as follows: 66.3 kDa protein in grey (3FGR), cephalosporin acylase (1OQZ) in pink, penicillin V acylase (3PVA) in yellow, conjugated bile acid hydrolase (2BJF) in green, penicillin G acylase (1K5S) in orange.