Representative tiling paths of PSI-BLAST searches initiated with the catalytic domain amino acid sequences of selected pART family members. PSI-BLAST searches were initiated with the catalytic domain amino acid sequences of the pARTs indicated on top as query sequences with the default threshold setting for the expect value of 0.005. Matching sequences from selected model organisms are indicated at the iteration in which they first appeared above threshold. pART subgroups are color coded as in Figure 2. Accession numbers of the indicated pARTs are listed in Figures 2 and 9. Species of origin is color-coded in the two letter abbreviation of the organism as follows: Homo sapiens (Hs) red, Drosophila melanogaster (Dm) and Anopheles gambiae (Ag) purple, Caenorrhabditis elegans (Ce) blue, Chilo iridescent virus (Ci) and Bacteriophage Aeh (Ba) brown.