Figure 2.

The nitrilase superfamily catalytic triad motifs. Consensus sequences flanking the invariant catalytic triad residues, glutamate, lysine and cysteine, were obtained by doing multiple sequence alignments within each branch [54]. Red letters on a yellow background indicate the same residue is conserved in all branches. Dark blue letters on light blue background indicate the residue is conserved in nine or more branches. Green background shows positions in which the conserved amino acid is found in six to eight of the branches. Upper case letters indicate 90% or greater consensus levels within a branch, whereas lower case are 50% or greater. Residue numbers are shown for the prototypical members of branches 1 to 12 and for the first listed member of branch 13.