title: Preliminary joint neutron time-of-flight and X-ray crystallographic study of human ABO(H) blood group A glycosyltransferase.
abstract: The biosyntheses of oligosaccharides and glycoconjugates are conducted by glycosyltransferases. These extraordinarily diverse and widespread enzymes catalyze the formation of glycosidic bonds through the transfer of a monosaccharide from a donor molecule to an acceptor molecule, with the stereochemistry about the anomeric carbon being either inverted or retained. Human ABO(H) blood group A α-1,3-N-acetylgalactosaminyltransferase (GTA) generates the corresponding antigen by the transfer of N-acetylgalactosamine from UDP-GalNAc to the blood group H antigen. To understand better how specific active-site-residue protons and hydrogen-bonding patterns affect substrate recognition and catalysis, neutron diffraction studies were initiated at the Protein Crystallography Station (PCS) at Los Alamos Neutron Science Center (LANSCE). A large single crystal was subjected to H/D exchange prior to data collection and time-of-flight neutron diffraction data were collected to 2.5 Å resolution at the PCS to ∼85% overall completeness, with complementary X-ray diffraction data collected from a crystal from the same drop and extending to 1.85 Å resolution. Here, the first successful neutron data collection from a glycosyltransferase is reported.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Schuman
authors.forename: S Z
authors.initials: SZ
authors.lastname: Fisher
authors.forename: A
authors.initials: A
authors.lastname: Kovalevsky
authors.forename: S N
authors.initials: SN
authors.lastname: Borisova
authors.forename: M M
authors.initials: MM
authors.lastname: Palcic
authors.forename: L
authors.initials: L
authors.lastname: Coates
authors.forename: P
authors.initials: P
authors.lastname: Langan
authors.forename: S V
authors.initials: SV
authors.lastname: Evans
mesh_terms: D000017:ABO Blood-Group System / Q000737:chemistry*; D002384:Catalysis; D003461:Crystallography; D018360:Crystallography, X-Ray / Q000379:methods; D006801:Humans; D006860:Hydrogen Bonding; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry*; D033363:Neutron Diffraction; D009502:Neutrons; D011506:Proteins; D011522:Protons
chemical_list: D000017:ABO Blood-Group System; D011506:Proteins; D011522:Protons; D017350:N-Acetylgalactosaminyltransferases; C003742:UDPgalactosamine-galactose acetylgalactosaminyltransferase