Structural changes in glycogen phosphorylase induced by phosphorylation.
A comparison of the refined crystal structures of dimeric glycogen phosphorylase b and a reveals structural changes that represent the first step in the activation of the enzyme. On phosphorylation of serine-14, the N-terminus of each subunit assumes an ordered helical conformation and binds to the surface of the dimer. The consequent structural changes at the N- and C-terminal regions lead to strengthened interactions between subunits and alter the binding sites for allosteric effectors and substrates.
Sprang
S R
SR
Department of Biochemistry, University of Texas Southwestern Medical Centre, Dallas 75235-9050.
Acharya
K R
KR
Goldsmith
E J
EJ
Stuart
D I
DI
Varvill
K
K
Fletterick
R J
RJ
Madsen
N B
NB
Johnson
L N
LN
D000249:Adenosine Monophosphate / Q000378:metabolism; D000495:Allosteric Site; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004789:Enzyme Activation; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006860:Hydrogen Bonding; D046911:Macromolecular Substances; D006005:Phosphorylases / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D011487:Protein Conformation; D014961:X-Ray Diffraction
D005958:Glucosephosphates; D046911:Macromolecular Substances; D010768:Phosphoserine; D000249:Adenosine Monophosphate; D019298:Glucose-6-Phosphate; D006005:Phosphorylases