This family consists of the oligosaccharyl transferase STT3 subunit and related proteins. The STT3 subunit is part of the oligosaccharyl transferase (OTase) complex of proteins and is required for its activity. In eukaryotes, OTase transfers a lipid-linked core-oligosaccharide to selected asparagine residues in the ER. In the archaea STT3 occurs alone, rather than in an OTase complex, and is required for N-glycosylation of asparagines.
Jiyao W et al.(2023). "The conserved domain database in 2023.",