Tyrosine-194 of glycogenin undergoes autocatalytic glucosylation but is not essential for catalytic function and activity.
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.
Alonso
M D
MD
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, FL 33101.
Lomako
J
J
Lomako
W M
WM
Whelan
W J
WJ
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*
D005960:Glucosides; D006023:Glycoproteins; D011994:Recombinant Proteins; C051887:glycogenin; D014443:Tyrosine; C040358:dodecyl maltoside; D006003:Glycogen; D005964:Glucosyltransferases