Members of this protein family average over 900 residues in length and appear to have multiple membrane-spanning helices in the N-terminal half. The extreme C-terminal region consists of a motif with consensus sequence MSEP, then a transmembrane alpha helix, then a short region with several basic residues. This region, hereby dubbed MSEP-CTERM, resembles other putative sorting signals associated with the archaeosortase/exosortase protein family (see TIGR04178). Genes for all members of this family are found next to a gene for exosortase K.
Jiyao W et al.(2023). "The conserved domain database in 2023.",