This domain is found at the C terminus of proteins such as the probable glycosyltransferase Gly (Swiss:Q9AEU2) that also contain the glycosyl transferase domain at the N terminus. It is also found N-terminal in numerous putative glycosyltransferases such as GalT1. GalT1 has been shown to catalyse the third step of Fap1 glycosylation [1]. This domain is structurally distinct from all known GT folds of glycosyltransferases and contains a metal binding site. This new glycosyltransferase fold has been named GT-D [1].

1: The highly conserved domain of unknown function 1792 has a distinct glycosyltransferase fold. Zhang H, Zhu F, Yang T, Ding L, Zhou M, Li J, Haslam SM, Dell A, Erlandsen H, Wu H; Nat Commun. 2014;5:4339. PMID:25023666