Multiple amino acid sequence alignment of the catalytic cores of the human pART family. The multiple sequence alignment was generated with T-Coffee and manually adjusted using the results of the PSI-BLAST, PSIPRED, and GenTHREADER analyses. Numbers at the sequence ends indicate the number of additional residues upstream and downstream of the alignment shown. Residues corresponding to the H Y E motif in the NAD binding crevice of diphtheria toxin are in red and marked by asterisks. The conserved β sheets and alpha helix are shaded in green and yellow. Conserved intron positions are marked in the multiple alignment using the same color-coding as in Figure 3. Conserved intron positions are indicated also above the alignment with arrows. Non-conserved intron positions are marked in blue in the alignment.