Download MendeleyA protein phosphorylation switch at the conserved allosteric site in GP.
Lin, K., Rath, V.L., Dai, S.C., Fletterick, R.J., Hwang, P.K.(1996) Science 273: 1539-1542
- PubMed: 8703213
- DOI: https://doi.org/10.1126/science.273.5281.1539
- Primary Citation of Related Structures:
1YGP - PubMed 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.
Organizational Affiliation:
Department of Biochemistry and Biophysics, University of California at San Francisco, 513 Parnassus, San Francisco, CA 94143, USA.
