Source:http://linkedlifedata.com/resource/pubmed/id/15767250
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
21
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| pubmed:dateCreated |
2005-5-23
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| pubmed:abstractText |
TtgV modulates the expression of the ttgGHI operon, which encodes an efflux pump that extrudes a wide variety of chemicals including mono- and binuclear aromatic hydrocarbons, aliphatic alcohols, and antibiotics of dissimilar chemical structure. Using a 'lacZ fusion to the ttgG promoter, we show that the most efficient in vivo inducers were 1-naphthol, 2,3-dihydroxynaphthalene, 4-nitrotoluene, benzonitrile, and indole. The thermodynamic parameters for the binding of different effector molecules to purified TtgV were determined by isothermal titration calorimetry. For the majority of effectors, the interaction was enthalpy-driven and counterbalance by unfavorable entropy changes. The TtgV-effector dissociation constants were found to vary between 2 and 890 mum. There was a relationship between TtgV affinity for the different effectors and their potential to induce gene expression in vivo, indicating that the effector binding constant is a major determinant for efficient efflux pump gene expression. Equilibrium dialysis and isothermal titration calorimetry studies indicated that a TtgV dimer binds one effector molecule. No evidence for the simultaneous binding of multiple effectors to TtgV was obtained. The binding of TtgV to a 63-bp DNA fragment containing its cognate operator was tight and entropy-driven (K(D) = 2.4 +/- 0.35 nm, DeltaH = 5.5 +/- 0.04 kcal/mol). The TtgV-DNA complex was shown to bind 1-napthol with an affinity comparable with the free soluble TtgV protein, K(D) = 4.8 +/- 0.19 and 3.0 +/- 0.15 mum, respectively. The biological relevance of this finding is discussed.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/1-naphthol,
http://linkedlifedata.com/resource/pubmed/chemical/2,3-dihydroxynaphthalene,
http://linkedlifedata.com/resource/pubmed/chemical/4-nitrotoluene,
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Bacterial,
http://linkedlifedata.com/resource/pubmed/chemical/Indoles,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Naphthols,
http://linkedlifedata.com/resource/pubmed/chemical/Nitriles,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Toluene,
http://linkedlifedata.com/resource/pubmed/chemical/TtgG protein, Pseudomonas putida,
http://linkedlifedata.com/resource/pubmed/chemical/TtgH protein, Pseudomonas putida,
http://linkedlifedata.com/resource/pubmed/chemical/benzonitrile,
http://linkedlifedata.com/resource/pubmed/chemical/beta-Galactosidase,
http://linkedlifedata.com/resource/pubmed/chemical/indole
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| pubmed:status |
MEDLINE
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| pubmed:month |
May
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| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
27
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| pubmed:volume |
280
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
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| pubmed:pagination |
20887-93
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:15767250-Bacterial Proteins,
pubmed-meshheading:15767250-Calorimetry,
pubmed-meshheading:15767250-DNA, Bacterial,
pubmed-meshheading:15767250-Escherichia coli,
pubmed-meshheading:15767250-Gene Expression Regulation, Bacterial,
pubmed-meshheading:15767250-Indoles,
pubmed-meshheading:15767250-Membrane Transport Proteins,
pubmed-meshheading:15767250-Naphthols,
pubmed-meshheading:15767250-Nitriles,
pubmed-meshheading:15767250-Operon,
pubmed-meshheading:15767250-Promoter Regions, Genetic,
pubmed-meshheading:15767250-Protein Binding,
pubmed-meshheading:15767250-Pseudomonas putida,
pubmed-meshheading:15767250-Recombinant Fusion Proteins,
pubmed-meshheading:15767250-Thermodynamics,
pubmed-meshheading:15767250-Toluene,
pubmed-meshheading:15767250-Transcription, Genetic,
pubmed-meshheading:15767250-beta-Galactosidase
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| pubmed:year |
2005
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| pubmed:articleTitle |
The multidrug efflux regulator TtgV recognizes a wide range of structurally different effectors in solution and complexed with target DNA: evidence from isothermal titration calorimetry.
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| pubmed:affiliation |
Department of Biochemistry and Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Profesor Albareda, 1, E-18008 Granada, Spain.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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