a novel gene defining a novel human udp - glcnac : gal / gl cnacβ 1 - 3galnac αβ1 , 6glcnac - transferase , termed c2 / 4gnt , with unique enzymatic properties is disclosed . the enzymatic activity of c2 / 4gnt is shown to be distinct from that of previously identified enzymes of this gene family . the invention discloses isolated dna molecules and dna constructs encoding c2 / 4gnt and derivatives thereof by way of amino acid deletion , substitution or insertion exhibiting c2 / 4gnt activity , as well as cloning and expression vectors including such dna , cells transfected with the vectors , and recombinant methods for providing c2 / 4gnt . the enzyme c2 / 4gnt and c2 / 4gnt - active derivatives thereof are disclosed , in particular soluble derivatives comprising the catalytically active domain of c2 / 4gnt . further , the invention discloses methods of obtaining 1 , 6 - n - acetyl glucosaminyl glycosylated saccharides , glycopeptides or glycoproteins by use of an enzymically active c2 / 4gnt protein or fusion protein thereof or by using cells stably transfected with a vector including dna encoding an enzymatically active c2 / 4gnt protein as an expression system for recombinant production of such glycopeptides or glycoproteins . also a method for the identification for the identification of dna sequence variations in the c2 / 4gnt gene by isolating dna from a patient , amplifying c2 / 4gnt - coding exons by pcr , and detecting the presence of dna sequence variation are disclosed .