Sequence logos of the nucleotide cyclase superfamily. Sequences were aligned using PROBE with a purge value of 150. The average information at conserved positions is 1.126 bits. The aspartate residues that likely interact with metal ions are located at motif 1, position 7 and motif 2, position 26. The asparagine and arginine residues that are believed to stabilize the transition state are located at motif 4, positions 9 and 13. Two positions that contribute to substrate specificity are located at motif 2, position 22 and motif 4, position 2. Also noted in this superfamily model were several highly conserved glycines, which commonly contribute needed flexibility to the catalytic domains of polypeptides.
