This domain is found in Archaeal Glycosylation B protein (AglB-Long) in A. fulgidus. When the domain, known as peripheral l (Pl), is combined with the central core (CC) and insertion (IS) sub-units, they form the C-terminal domain. It is thought that the C-terminal domain may contribute toward the increased thermal stability of the AglB proteins in the hyper-thermophilic [1].

1: Crystal structure of the C-terminal globular domain of the third paralog of the Archaeoglobus fulgidus oligosaccharyltransferases. Matsumoto S, Shimada A, Kohda D; BMC Struct Biol. 2013;13:11. PMID:23815857

2: Crystal structures of an archaeal oligosaccharyltransferase provide insights into the catalytic cycle of N-linked protein glycosylation. Matsumoto S, Shimada A, Nyirenda J, Igura M, Kawano Y, Kohda D; Proc Natl Acad Sci U S A. 2013;110:17868-17873. PMID:24127570