This domain occurs in archaeal species. Most domains in this family end with a motif PGF, after which the member sequences change in character to low-complexity sequence (usually Thr-rich) for about 40 residues. The low complexity region usually is followed by a PGF-CTERM domain, which we suggest is the recognition sequence for archaeosortase A, a putative protein-sorting transpeptidase. The similarity between the PGF motif in this domain and in the PGF-CTERM domain is highly suggestive.
