1qvt: Difference between revisions

Revision as of 15:44, 21 February 2008

CRYSTAL STRUCTURE OF THE MULTIDRUG BINDING TRANSCRIPTIONAL REPRESSOR QACR BOUND TO THE DRUG PROFLAVINE

OverviewOverview

The structural basis of simultaneous binding of two or more different drugs by any multidrug-binding protein is unknown and also how this can lead to a noncompetitive, uncompetitive or cooperative binding mechanism. Here, we describe the crystal structure of the Staphylococcus aureus multidrug-binding transcription repressor, QacR, bound simultaneously to ethidium (Et) and proflavin (Pf). The structure underscores the plasticity of the multidrug-binding pocket and reveals an alternative, Pf-induced binding mode for Et. To monitor the simultaneous binding of Pf and Et to QacR, as well as to determine the effects on the binding affinity of one drug when the other drug is prebound, a novel application of near-ultraviolet circular dichroism (UVCD) was developed. The UVCD equilibrium-binding studies revealed identical affinities of Pf for QacR in the presence or absence of Et, but significantly diminished affinity of Et for QacR when Pf is prebound, findings that are readily explicable by their structures. The principles for simultaneous binding of two different drugs discerned here are likely employed by the multidrug efflux transporters.

About this StructureAbout this Structure

1QVT is a Single protein structure of sequence from Staphylococcus aureus with and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

Structural mechanism of the simultaneous binding of two drugs to a multidrug-binding protein., Schumacher MA, Miller MC, Brennan RG, EMBO J. 2004 Aug 4;23(15):2923-30. Epub 2004 Jul 15. PMID:15257299

Page seeded by OCA on Thu Feb 21 14:44:12 2008

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OCA

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-[[Image:1qvt.gif|left|200px]]<br /><applet load="1qvt" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1qvt.gif|left|200px]]<br /><applet load="1qvt" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1qvt, resolution 2.89&Aring;" />
 '''CRYSTAL STRUCTURE OF THE MULTIDRUG BINDING TRANSCRIPTIONAL REPRESSOR QACR BOUND TO THE DRUG PROFLAVINE'''<br />
 ==Overview==
-The structural basis of simultaneous binding of two or more different, drugs by any multidrug-binding protein is unknown and also how this can, lead to a noncompetitive, uncompetitive or cooperative binding mechanism., Here, we describe the crystal structure of the Staphylococcus aureus, multidrug-binding transcription repressor, QacR, bound simultaneously to, ethidium (Et) and proflavin (Pf). The structure underscores the plasticity, of the multidrug-binding pocket and reveals an alternative, Pf-induced, binding mode for Et. To monitor the simultaneous binding of Pf and Et to, QacR, as well as to determine the effects on the binding affinity of one, drug when the other drug is prebound, a novel application of, near-ultraviolet circular dichroism (UVCD) was developed. The UVCD, equilibrium-binding studies revealed identical affinities of Pf for QacR, in the presence or absence of Et, but significantly diminished affinity of, Et for QacR when Pf is prebound, findings that are readily explicable by, their structures. The principles for simultaneous binding of two different, drugs discerned here are likely employed by the multidrug efflux, transporters.
+The structural basis of simultaneous binding of two or more different drugs by any multidrug-binding protein is unknown and also how this can lead to a noncompetitive, uncompetitive or cooperative binding mechanism. Here, we describe the crystal structure of the Staphylococcus aureus multidrug-binding transcription repressor, QacR, bound simultaneously to ethidium (Et) and proflavin (Pf). The structure underscores the plasticity of the multidrug-binding pocket and reveals an alternative, Pf-induced binding mode for Et. To monitor the simultaneous binding of Pf and Et to QacR, as well as to determine the effects on the binding affinity of one drug when the other drug is prebound, a novel application of near-ultraviolet circular dichroism (UVCD) was developed. The UVCD equilibrium-binding studies revealed identical affinities of Pf for QacR in the presence or absence of Et, but significantly diminished affinity of Et for QacR when Pf is prebound, findings that are readily explicable by their structures. The principles for simultaneous binding of two different drugs discerned here are likely employed by the multidrug efflux transporters.
 ==About this Structure==
-QVT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus] with SO4 and PRL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1QVT OCA].
+QVT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=PRL:'>PRL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QVT OCA].
 ==Reference==
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 [[Category: Single protein]]
 [[Category: Staphylococcus aureus]]
-[[Category: Brennan, R.G.]]
+[[Category: Brennan, R G.]]
-[[Category: Miller, M.C.]]
+[[Category: Miller, M C.]]
-[[Category: Schumacher, M.A.]]
+[[Category: Schumacher, M A.]]
 [[Category: PRL]]
 [[Category: SO4]]
@@ Line 23: / Line 23: @@
 [[Category: transcription]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:02:31 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:12 2008''