This family is an archaeal variant of the (normally bacterial) putative protein-sorting integral membrane protein exosortase, hence archaeosortase. In species a member of this family, its PGF-CTERM cognate sequence (TIGR04126) occurs at the C-termini of from two to over fifty proteins per genome. Those target proteins may not share homology to each other in regions N-terminal to the PGF-CTERM region.