Statements in which the resource exists.
SubjectPredicateObjectContext
pubmed-article:12767240rdf:typepubmed:Citationlld:pubmed
pubmed-article:12767240lifeskim:mentionsumls-concept:C0085495lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C0008633lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C1711351lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C0332120lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C0441712lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C0051637lld:lifeskim
pubmed-article:12767240lifeskim:mentionsumls-concept:C0596448lld:lifeskim
pubmed-article:12767240pubmed:issue21lld:pubmed
pubmed-article:12767240pubmed:dateCreated2003-5-27lld:pubmed
pubmed-article:12767240pubmed:abstractTextThe aminoglycoside 6'-N-acetyltransferase AAC(6')-Ii from Enterococcus faecium is an important microbial resistance determinant and a member of the GCN5-related N-acetyltransferase (GNAT) superfamily. We report here the further characterization of this enzyme in terms of the kinetic mechanism of acetyl transfer and identification of rate-contributing step(s) in catalysis, as well as investigations into the binding of both acetyl-CoA and aminoglycoside substrates to the AAC(6')-Ii dimer. Product and dead-end inhibition studies revealed that AAC(6')-Ii follows an ordered bi-bi ternary complex mechanism with acetyl-CoA binding first followed by antibiotic. Solvent viscosity studies demonstrated that aminoglycoside binding and product release govern the rate of acetyl transfer, as evidenced by changes in both the k(cat)/K(b) for aminoglycoside and k(cat), respectively, with increasing solvent viscosity. Solvent isotope effects were consistent with our viscosity studies that diffusion-controlled processes and not the chemical step were rate-limiting in drug modification. The patterns of partial and mixed inhibition observed during our mechanistic studies were followed up by investigating the possibility of subunit cooperativity in the AAC(6')-Ii dimer. Through the use of AAC-Trp(164) --> Ala, an active mutant which exists as a monomer in solution, the partial nature of the competitive inhibition observed in wild-type dead-end inhibition studies was alleviated. Isothermal titration calorimetry studies also indicated two nonequivalent antibiotic binding sites for the AAC(6')-Ii dimer but only one binding site for the Trp(164) --> Ala mutant. Taken together, these results demonstrate subunit cooperativity in the AAC(6')-Ii dimer, with possible relevance to other oligomeric members of the GNAT superfamily.lld:pubmed
pubmed-article:12767240pubmed:languageenglld:pubmed
pubmed-article:12767240pubmed:journalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:citationSubsetIMlld:pubmed
pubmed-article:12767240pubmed:chemicalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:chemicalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:chemicalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:chemicalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:chemicalhttp://linkedlifedata.com/r...lld:pubmed
pubmed-article:12767240pubmed:statusMEDLINElld:pubmed
pubmed-article:12767240pubmed:monthJunlld:pubmed
pubmed-article:12767240pubmed:issn0006-2960lld:pubmed
pubmed-article:12767240pubmed:authorpubmed-author:WrightGerard...lld:pubmed
pubmed-article:12767240pubmed:authorpubmed-author:NorthropDexte...lld:pubmed
pubmed-article:12767240pubmed:authorpubmed-author:DrakerKari-an...lld:pubmed
pubmed-article:12767240pubmed:issnTypePrintlld:pubmed
pubmed-article:12767240pubmed:day3lld:pubmed
pubmed-article:12767240pubmed:volume42lld:pubmed
pubmed-article:12767240pubmed:ownerNLMlld:pubmed
pubmed-article:12767240pubmed:authorsCompleteYlld:pubmed
pubmed-article:12767240pubmed:pagination6565-74lld:pubmed
pubmed-article:12767240pubmed:dateRevised2006-11-15lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:meshHeadingpubmed-meshheading:12767240...lld:pubmed
pubmed-article:12767240pubmed:year2003lld:pubmed
pubmed-article:12767240pubmed:articleTitleKinetic mechanism of the GCN5-related chromosomal aminoglycoside acetyltransferase AAC(6')-Ii from Enterococcus faecium: evidence of dimer subunit cooperativity.lld:pubmed
pubmed-article:12767240pubmed:affiliationAntimicrobial Research Centre, Department of Biochemistry, McMaster University, 1200 Main Street West, Ontario L8N 3Z5, Canada.lld:pubmed
pubmed-article:12767240pubmed:publicationTypeJournal Articlelld:pubmed
pubmed-article:12767240pubmed:publicationTypeResearch Support, Non-U.S. Gov'tlld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed
http://linkedlifedata.com/r...pubmed:referesTopubmed-article:12767240lld:pubmed