Models TIGR03110, TIGR03111, and TIGR03112 describe a three-gene system found in several Gram-positive bacteria, where TIGR03110 (XrtG) is distantly related to a putative transpeptidase, exosortase (TIGR02602). This model describes a small clade that correlates by both gene clustering and phyletic pattern, although imperfectly, to the three gene system. Both this narrow clade, and the larger set of full-length homologous integral membrane proteins, have an especially well-conserved region near the C-terminus with an invariant tyrosine. The function is unknown.
Jiyao W et al.(2023). "The conserved domain database in 2023.",