Publication Date:
1989-08-04
Description:
The crystal structure of glycogen phosphorylase a complexed with its substrates, orthophosphate and maltopentaose, has been determined and refined at a resolution of 2.8 angstroms. With oligosaccaride bound at the glycogen storage site, the phosphate ion binds at the catalytic site and causes the regulatory and catalytic domains to separate with the loss of stabilizing interactions between them. Homotropic cooperativity between the active sites of the allosteric dimer results from rearrangements in isologous contacts between symmetry-related helices in the subunit interface. The conformational changes in the core of the interface are correlated with those observed on covalent activation by phosphorylation at Ser14 (phosphorylase b----a).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Goldsmith, E J -- Sprang, S R -- Hamlin, R -- Xuong, N H -- Fletterick, R J -- DK31507-05/DK/NIDDK NIH HHS/ -- GM00085-05/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1989 Aug 4;245(4917):528-32.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2756432" target="_blank"〉PubMed〈/a〉
Keywords:
Allosteric Site
;
Amino Acid Sequence
;
Binding Sites
;
Catalysis
;
Crystallization
;
Crystallography
;
Enzyme Activation
;
Glucosephosphates/metabolism
;
Glycogen/metabolism
;
Macromolecular Substances
;
Molecular Sequence Data
;
Molecular Structure
;
Oligosaccharides
;
Phosphates/metabolism
;
Phosphorylase a/*metabolism
;
Phosphorylases/*metabolism
;
Protein Conformation
;
X-Ray Diffraction
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
