Publication Date:
1996-09-13
Description:
A phosphorylation-initiated mechanism of local protein refolding activates yeast glycogen phosphorylase (GP). Refolding of the phosphorylated amino-terminus was shown to create a hydrophobic cluster that wedges into the subunit interface of the enzyme to trigger activation. The phosphorylated threonine is buried in the allosteric site. The mechanism implicates glucose 6-phosphate, the allosteric inhibitor, in facilitating dephosphorylation by dislodging the buried covalent phosphate through binding competition. Thus, protein phosphorylation-dephosphorylation may also be controlled through regulation of the accessibility of the phosphorylation site to kinases and phosphatases. In mammalian glycogen phosphorylase, phosphorylation occurs at a distinct locus. The corresponding allosteric site binds a ligand activator, adenosine monophosphate, which triggers activation by a mechanism analogous to that of phosphorylation in the yeast enzyme.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lin, K -- Rath, V L -- Dai, S C -- Fletterick, R J -- Hwang, P K -- DK32822/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1996 Sep 13;273(5281):1539-42.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Biophysics, University of California at San Francisco, 513 Parnassus, San Francisco, CA 94143, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8703213" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Monophosphate/metabolism
;
Allosteric Site
;
Amino Acid Sequence
;
Animals
;
Crystallography, X-Ray
;
Enzyme Activation
;
Enzyme Inhibitors/metabolism/pharmacology
;
Glucose-6-Phosphate
;
Glucosephosphates/metabolism/pharmacology
;
Models, Molecular
;
Molecular Sequence Data
;
Phosphorylases/antagonists & inhibitors/*chemistry/*metabolism
;
Phosphorylation
;
*Protein Conformation
;
Protein Folding
;
Protein Structure, Secondary
;
Saccharomyces cerevisiae/enzymology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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