title: Tyrosine-194 of glycogenin undergoes autocatalytic glucosylation but is not essential for catalytic function and activity.
abstract: Glycogenin is the protein primer for glycogen synthesis. By autocatalytic transglucosylation from UDPglucose, it creates a malto-octaose chain attached to its Tyr-194. It has been uncertain whether the autocatalysis includes the addition of the first glucose residue to Tyr-194. We now show this to be the case. However, we also demonstrate, contrary to a claim by others, that Tyr-194 is not necessary for the catalytic function and activity of glycogenin.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, FL 33101.
authors.forename: M D
authors.initials: MD
authors.lastname: Alonso
authors.forename: J
authors.initials: J
authors.lastname: Lomako
authors.forename: W M
authors.initials: WM
authors.lastname: Lomako
authors.forename: W J
authors.initials: WJ
authors.lastname: Whelan
mesh_terms: D000818:Animals; D002384:Catalysis; D005960:Glucosides / Q000378:metabolism; D005964:Glucosyltransferases; D006003:Glycogen / Q000096:biosynthesis; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006031:Glycosylation; D016296:Mutagenesis; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D005960:Glucosides; D006023:Glycoproteins; D011994:Recombinant Proteins; C051887:glycogenin; D014443:Tyrosine; C040358:dodecyl maltoside; D006003:Glycogen; D005964:Glucosyltransferases