| http://purl.uniprot.org/citations/10545198 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/10545198 | http://www.w3.org/2000/01/rdf-schema#comment | "The contributions to catalysis of the conserved catalytic aspartate (Asp149) in the phosphorylase kinase catalytic subunit (PhK; residues 1-298) have been studied by kinetic and crystallographic methods. Kinetic studies in solvents of different viscosity show that PhK, like cyclic AMP dependent protein kinase, exhibits a mechanism in which the chemical step of phosphoryl transfer is fast and the rate-limiting step is release of the products, ADP and phosphoprotein, and possibly viscosity-dependent conformational changes. Site-directed mutagenesis of Asp149 to Ala and Asn resulted in enzymes with a small increase in K(m) for glycogen phosphorylase b (GPb) and ATP substrates and dramatic decreases in k(cat) (1.3 x 10(4) for Asp149Ala and 4.7 x 10(3) for Asp149Asn mutants, respectively). Viscosometric kinetic measurements with the Asp149Asn mutant showed a reduction in the rate-limiting step for release of products by 4.5 x 10(3) and a significant decrease (possibly as great as 2.2 x 10(3)) in the rate constant characterizing the chemical step. The date combined with the crystallographic evidence for the ternary PhK-AMPPNP-peptide complex [Lowe et al. (1997) EMBO J. 6, 6646-6658] provide powerful support for the role of the carboxyl of Asp149 in binding and orientation of the substrate and in catalysis of phosphoryl transfer. The constitutively active subunit PhK has a glutamate (Glu182) residue in the activation segment, in place of a phosphorylatable serine, threonine, or tyrosine residue in other protein kinases that are activated by phosphorylation. Site-directed mutagenesis of Glu182 and other residues involved in a hydrogen bond network resulted in mutant proteins (Glu182Ser, Arg148Ala, and Tyr206Phe) with decreased catalytic efficiency (approximate average decrease in k(cat)/K(m) by 20-fold). The crystal structure of the mutant Glu182Ser at 2.6 A resolution showed a phosphate dianion about 2.6 A from the position previously occupied by the carboxylate of Glu182. There was no change in tertiary structure from the native protein, but the activation segment in the region C-terminal to residue 182 showed increased disorder, indicating that correct localization of the activation segment is necessary in order to recognize and present the protein substrate for catalysis."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.org/dc/terms/identifier | "doi:10.1021/bi991454f"xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Noble M.E."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Lowe G."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Johnson L.N."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Owen D.J."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Lowe E.D."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Oikonomakos N.G."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/author | "Skamnaki V.T."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/date | "1999"xsd:gYear |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/name | "Biochemistry"xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/pages | "14718-14730"xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/title | "Catalytic mechanism of phosphorylase kinase probed by mutational studies."xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://purl.uniprot.org/core/volume | "38"xsd:string |
| http://purl.uniprot.org/citations/10545198 | http://www.w3.org/2004/02/skos/core#exactMatch | http://purl.uniprot.org/pubmed/10545198 |
| http://purl.uniprot.org/citations/10545198 | http://xmlns.com/foaf/0.1/primaryTopicOf | https://pubmed.ncbi.nlm.nih.gov/10545198 |
| http://purl.uniprot.org/uniprot/#_P00518-mappedCitation-10545198 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/10545198 |
| http://purl.uniprot.org/uniprot/P00518 | http://purl.uniprot.org/core/mappedCitation | http://purl.uniprot.org/citations/10545198 |