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http://purl.uniprot.org/citations/12051945http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/12051945http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/12051945http://www.w3.org/2000/01/rdf-schema#comment"The active site of glucosamine-6-phosphate deaminase from Escherichia coli (GlcN6P deaminase, EC 3.5.99.6) has a complex lid formed by two antiparallel beta-strands connected by a helix-loop segment (158-187). This motif contains Arg172, which is a residue involved in binding the substrate in the active-site, and three residues that are part of the allosteric site, Arg158, Lys160 and Thr161. This dual binding role of the motif forming the lid suggests that it plays a key role in the functional coupling between active and allosteric sites. Previous crystallographic work showed that the temperature coefficients of the active-site lid are very large when the enzyme is in its T allosteric state. These coefficients decrease in the R state, thus suggesting that this motif changes its conformational flexibility as a consequence of the allosteric transition. In order to explore the possible connection between the conformational flexibility of the lid and the function of the deaminase, we constructed the site-directed mutant Phe174-Ala. Phe174 is located at the C-end of the lid helix and its side-chain establishes hydrophobic interactions with the remainder of the enzyme. The crystallographic structure of the T state of Phe174-Ala deaminase, determined at 2.02 A resolution, shows no density for the segment 162-181, which is part of the active-site lid (PDB 1JT9). This mutant form of the enzyme is essentially inactive in the absence of the allosteric activator, N-acetylglucosamine-6-P although it recovers its activity up to the wild-type level in the presence of this ligand. Spectrometric and binding studies show that inactivity is due to the inability of the active-site to bind ligands when the allosteric site is empty. These data indicate that the conformational flexibility of the active-site lid critically alters the binding properties of the active site, and that the occupation of the allosteric site restores the lid conformational flexibility to a functional state."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.org/dc/terms/identifier"doi:10.1016/s0022-2836(02)00096-7"xsd:string
http://purl.uniprot.org/citations/12051945http://purl.org/dc/terms/identifier"doi:10.1016/s0022-2836(02)00096-7"xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Sosa-Peinado A."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Sosa-Peinado A."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Horjales E."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Horjales E."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Rudino-Pinera E."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Rudino-Pinera E."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Bustos-Jaimes I."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Bustos-Jaimes I."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Calcagno M.L."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/author"Calcagno M.L."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/date"2002"xsd:gYear
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/date"2002"xsd:gYear
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/name"J. Mol. Biol."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/name"J. Mol. Biol."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/pages"183-189"xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/pages"183-189"xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/title"On the role of the conformational flexibility of the active-site lid on the allosteric kinetics of glucosamine-6-phosphate deaminase."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/title"On the role of the conformational flexibility of the active-site lid on the allosteric kinetics of glucosamine-6-phosphate deaminase."xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/volume"319"xsd:string
http://purl.uniprot.org/citations/12051945http://purl.uniprot.org/core/volume"319"xsd:string
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