Structural and Biochemical Characterization of the Mammalian Glycosyltransferases, N-acetylglucosaminyltransferase II and Protein O-fucosyltransferase 1

Glycosyltransferases are the enzymes responsible for the biosynthesis of glycans. Each of these enzymes catalyzes the transfer of a sugar moiety from a donor molecule to a specific acceptor substrate. This study focuses on determination of the X-ray crystallographic structures of two mammalian glycosyltransferases with emphasis on understanding the structural basis for the recognition of their acceptor substrates. This effort yielded the X-ray crystal structures of the enzymes N-acetylglucosaminyltransferase II (GnT II) and protein O-fucosyltransferase 1 (POFUT1) in complexes with their substrates. This study also saw technical innovations, notably the use of the piggyBac transposon for establishing stable mammalian cell cultures for protein expression.