Identification of the molecular trigger for allosteric activation in glycogen phosphorylase.
Activation of protein function through phosphorylation can be mimicked by the engineering of specific metal binding sites. The addition of two histidine residues to glycogen phosphorylase allows enzymatic activation by transition metals in a cooperative and allosteric manner. Crystal structures of the metallo-enzyme have been determined and show that the structural transition induced upon metal binding (Ni2+) is, in part, analogous to the mode of activation of the native enzyme. The designed metal activation site allows assignment of the structural changes which trigger activation in this allosteric enzyme and, further, provide insight into the evolutionary development of multiple activation sites.
Browner
M F
MF
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448, USA.
Hackos
D
D
Fletterick
R
R
D000494:Allosteric Regulation; D000818:Animals; D001665:Binding Sites; D005075:Biological Evolution; D002413:Cations, Divalent / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004789:Enzyme Activation / Q000187:drug effects; D009124:Muscle Proteins / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D009532:Nickel / Q000378:metabolism / Q000494:pharmacology; D006005:Phosphorylases / Q000737:chemistry*; D011487:Protein Conformation; D011817:Rabbits
D002413:Cations, Divalent; D009124:Muscle Proteins; D009532:Nickel; D006005:Phosphorylases