Members of this protein family have a novel N-terminal sequence region. The C-terminal region of these proteins share homology with proteins in the PpiC-type peptidyl-prolyl cis-trans isomerase entry (). However, proteins in this family are not included in the IPR000297 entry, suggesting an origin within a branch of the PpiC family but subsequent neofunctionalisation with a rapid change of sequence. The genome context for members always includes an ATP-grasp enzyme associated with peptide modification and a short polypeptide likely to be the modification target.
