GNT1 is a fungal enzyme that belongs to the GT 8 family. N-acetylglucosaminyltransferase is a fungal enzyme that catalyzes the addition of N-acetyl-D-glucosamine to mannotetraose side chains by an alpha 1-2 linkage during the synthesis of mannan. The N-acetyl-D-glucosamine moiety in mannan plays a role in the attachment of mannan to asparagine residues in proteins. The mannotetraose and its N-acetyl-D-glucosamine derivative side chains of mannan are the principle immunochemical determinants on the cell surface. N-acetylglucosaminyltransferase is a member of glycosyltransferase family 8, which are, based on the relative anomeric stereochemistry of the substrate and product in the reaction catalyzed, retaining glycosyltransferases.
DDE superfamily endonuclease. This family of proteins are related to pfam00665 and are probably endonucleases of the DDE superfamily. Transposase proteins are necessary for efficient DNA transposition. This domain is a member of the DDE superfamily, which contain three carboxylate residues that are believed to be responsible for coordinating metal ions needed for catalysis. The catalytic activity of this enzyme involves DNA cleavage at a specific site followed by a strand transfer reaction.
Glycogenin belongs the GT 8 family and initiates the biosynthesis of glycogen. Glycogenin initiates the biosynthesis of glycogen by incorporating glucose residues through a self-glucosylation reaction at a Tyr residue, and then acts as substrate for chain elongation by glycogen synthase and branching enzyme. It contains a conserved DxD motif and an N-terminal beta-alpha-beta Rossmann-like fold that are common to the nucleotide-binding domains of most glycosyltransferases. The DxD motif is essential for coordination of the catalytic divalent cation, most commonly Mn2+. Glycogenin can be classified as a retaining glycosyltransferase, based on the relative anomeric stereochemistry of the substrate and product in the reaction catalyzed. It is placed in glycosyltransferase family 8 which includes lipopolysaccharide glucose and galactose transferases and galactinol synthases.