Structural highlights
Function[GLYG_RABIT] Self-glucosylates, via an inter-subunit mechanism, to form an oligosaccharide primer that serves as substrate for glycogen synthase. Publication Abstract from PubMedThe X-ray structure of rabbit glycogenin containing the T82M (T83M according to previous authors amino acid numbering [1]) mutation causing glycogenosis showed the loss of Thr82 hydrogen bond to Asp162, the residue involved in the activation step of the glucose transfer reaction mechanism. Autoglucosylation, maltoside transglucosylation and UDP-glucose hydrolyzing activities were abolished even though affinity and interactions with UDP-glucose and positioning of Tyr194 acceptor were conserved. Substitution of Thr82 for serine but not for valine restored the maximum extent of autoglucosylation as well as transglucosylation and UDP-glucose hydrolysis rate. Results provided evidence sustaining the essential role of the lost single hydrogen bond for UDP-glucose activation leading to glycogenin-bound glycogen primer synthesis. Structural and biochemical insight into glycogenin inactivation by the glycogenosis-causing T82M mutation.,Carrizo ME, Romero JM, Issoglio FM, Curtino JA FEBS Lett. 2012 Jan 3. PMID:22226635[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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