A novel polypeptide having a beta 1,3-N-acetylglucosamine transferase activity; a process for producing this polypeptide; a DNA encoding this polypeptide; a recombinant vector having this DNA integrated therein; a transformant having this recombinant vector; a process for producing a sugar chain or a glycoconjugate by using the above polypeptide; a process for producing a sugar chain or a glycoconjugate by utilizing the above transformant; an antibody recognizing the above polypeptide; a method for screening a substance capable of changing the expression of the gene encoding the polypeptide; and a method for screening a substance capable of changing the activity of the polypeptide.
