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A protein phosphorylation switch at the conserved allosteric site in GP.
- Source :
-
Science (New York, N.Y.) [Science] 1996 Sep 13; Vol. 273 (5281), pp. 1539-42. - Publication Year :
- 1996
-
Abstract
- 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.
- Subjects :
- Adenosine Monophosphate metabolism
Allosteric Site
Amino Acid Sequence
Animals
Crystallography, X-Ray
Enzyme Activation
Enzyme Inhibitors metabolism
Enzyme Inhibitors pharmacology
Glucose-6-Phosphate
Glucosephosphates metabolism
Glucosephosphates pharmacology
Models, Molecular
Molecular Sequence Data
Phosphorylases antagonists & inhibitors
Phosphorylation
Protein Folding
Protein Structure, Secondary
Saccharomyces cerevisiae enzymology
Phosphorylases chemistry
Phosphorylases metabolism
Protein Conformation
Subjects
Details
- Language :
- English
- ISSN :
- 0036-8075
- Volume :
- 273
- Issue :
- 5281
- Database :
- MEDLINE
- Journal :
- Science (New York, N.Y.)
- Publication Type :
- Academic Journal
- Accession number :
- 8703213
- Full Text :
- https://doi.org/10.1126/science.273.5281.1539