Archaeosortase A of 303 aas and 7 or 8 TMSs, probably in a 4 + 4 TMS arrangement.  It is at ranspeptidase that recognizes and modifies its substrate by proteolytic cleavage of a sorting signal. Following cleavage, a covalent intermediate is formed via a thioester bond between the archaeosortase and its substrate, which is then transferred and covalently attached to the cell membrane. This sortase recognizes a tripartite structure consisting of a conserved Pro-Gly-Phe (PGF) motif, followed by a transmembrane alpha helix domain and a cluster of basic residues, usually at the C-terminus of target proteins. Confirmed substrates include the cell surface S-layer glycoprotein Csg and HVO_0405 (Abdul Halim et al. 2013, Abdul Halim et al. 2015, Abdul Halim et al. 2017).
ArtA is required for the C-terminal processing of Csg and for its lipidation and attachment to the archaeal plasma membrane (Abdul Halim et al. 2013, Abdul Halim et al. 2015).
It is also required for the processing of HVO_0405, which contains an atypical central tripartite structure (Abdul Halim et al. 2017).