Glycosyltransferase like family 2. Members of this family of prokaryotic proteins include putative glucosyltransferase, which are involved in bacterial capsule biosynthesis.
N-terminal domain of Chondroitin polymerase functions as a GalNAc transferase. Chondroitin polymerase is a two domain, bi-functional protein. The N-terminal domain functions as a GalNAc transferase. The bacterial chondroitin polymerase catalyzes elongation of the chondroitin chain by alternatively transferring the GlcUA and GalNAc moiety from UDP-GlcUA and UDP-GalNAc to the non-reducing ends of the chondroitin chain. The enzyme consists of N-terminal and C-terminal domains in which the two active sites catalyze the addition of GalNAc and GlcUA, respectively. Chondroitin chains range from 40 to over 100 repeating units of the disaccharide. Sulfated chondroitins are involved in the regulation of various biological functions such as central nervous system development, wound repair, infection, growth factor signaling, and morphogenesis, in addition to its conventional structural roles. In Caenorhabditis elegans, chondroitin is an essential factor for the worm to undergo cytokinesis and cell division. Chondroitin is synthesized as proteoglycans, sulfated and secreted to the cell surface or extracellular matrix.
N-terminal domain of galactosyltransferase. This is the N-terminal domain of a family of galactosyltransferases from a wide range of Metazoa with three related galactosyltransferases activities, all three of which are possessed by one sequence in some cases. EC:2.4.1.90, N-acetyllactosamine synthase; EC:2.4.1.38, Beta-N-acetylglucosaminyl-glycopeptide beta-1,4- galactosyltransferase; and EC:2.4.1.22 Lactose synthase. Note that N-acetyllactosamine synthase is a component of Lactose synthase along with alpha-lactalbumin, in the absence of alpha-lactalbumin EC:2.4.1.90 is the catalyzed reaction.
pp-GalNAc-T initiates the formation of mucin-type O-linked glycans. UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferases (pp-GalNAc-T) initiate the formation of mucin-type, O-linked glycans by catalyzing the transfer of alpha-N-acetylgalactosamine (GalNAc) from UDP-GalNAc to hydroxyl groups of Ser or Thr residues of core proteins to form the Tn antigen (GalNAc-a-1-O-Ser/Thr). These enzymes are type II membrane proteins with a GT-A type catalytic domain and a lectin domain located on the lumen side of the Golgi apparatus. In human, there are 15 isozymes of pp-GalNAc-Ts, representing the largest of all glycosyltransferase families. Each isozyme has unique but partially redundant substrate specificity for glycosylation sites on acceptor proteins.