[2] Knockout of the archaeosortase A (artA) gene, or permutation of the motif Pro-Gly-Phe (PGF) to Pro-Phe-Gly in the S-layer glycoprotein, blocks attachment of the lipid moiety as well as blocking removal of the PGF-CTERM protein-sorting domain.
The names of both families of proteins reflect roles analogous to sortases in Gram-positive bacteria, with which they share no sequence homology.
The sequences of archaeosortases and exosortases consists mostly of hydrophobic transmembrane helices, which sortases lack.
Archaeosortases fall into a number of distinct subtypes, each responsible for recognizing sorting signals with a different signature motif.
Invariant residues shared by all archaeosortases and exosortases include a Cys and an Arg.