2jsc

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(New page: 200px<br /><applet load="2jsc" size="350" color="white" frame="true" align="right" spinBox="true" caption="2jsc" /> '''NMR structure of the cadmium metal-sensor CM...)
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==Overview==
==Overview==
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CmtR from Mycobacterium tuberculosis is a winged helical DNA-binding, repressor of the ArsR-SmtB metal-sensing family that senses cadmium and, lead. Cadmium-CmtR is a dimer with the metal bound to Cys102 from the, carboxyl-terminal region of one subunit and two Cys associated with helix, alphaR from the other sub-unit, forming a symmetrical pair of, cadmium-binding sites. This is a significant novelty in the ArsR-SmtB, family. The structure of the dimer could be solved at 312K. The apo, protein at the same temperature is still a dimer but it experiences a, large conformational exchange at the dimer interface and within each, monomer. This is monitored by an overall decrease of the number of NOEs, and by an increase of H2O-D2O exchange rates, especially at the dimeric, interface, in the apo form with respect to the Cd-bound state. The, C-terminal tail region is completely unstructured in both apo and cadmium, forms but becomes less mobile in the cadmium-bound protein due to the, recruitment of Cys102 as a metal-ligand. DNA binds to the apo dimer with a, ratio 1:3 at mM concentration. Addition of cadmium to the apo-CmtR DNA, complex causes DNA detachment, restoring the NMR spectrum of free, cadmium-CmtR. Cadmium-binding across the dimer interface impairs, DNA-association by excluding the apo-conformers suited to bind DNA.
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CmtR from Mycobacterium tuberculosis is a winged helical DNA-binding repressor of the ArsR-SmtB metal-sensing family that senses cadmium and lead. Cadmium-CmtR is a dimer with the metal bound to Cys-102 from the C-terminal region of one subunit and two Cys associated with helix alphaR from the other subunit, forming a symmetrical pair of cadmium-binding sites. This is a significant novelty in the ArsR-SmtB family. The structure of the dimer could be solved at 312 K. The apoprotein at the same temperature is still a dimer, but it experiences a large conformational exchange at the dimer interface and within each monomer. This is monitored by an overall decrease of the number of nuclear Overhauser effects and by an increase of H(2)O-D(2)O exchange rates, especially at the dimeric interface, in the apo form with respect to the cadmium-bound state. The C-terminal tail region is completely unstructured in both apo and cadmium forms but becomes less mobile in the cadmium-bound protein due to the recruitment of Cys-102 as a metal-ligand. DNA binds to the apo dimer with a ratio 1:3 at millimolar concentration. Addition of cadmium to the apo-CmtR-DNA complex causes DNA detachment, restoring the NMR spectrum of free cadmium-CmtR. Cadmium binding across the dimer interface impairs DNA association by excluding the apo-conformers suited to bind DNA.
==About this Structure==
==About this Structure==
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==Reference==
==Reference==
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NMR structural analysis of cadmium-sensing by winged helix repressor CMTR., Banci L, Bertini I, Cantini F, Ciofi-Baffoni S, Cavet JS, Dennison C, Graham A, Harvie DR, Robinson NJ, J Biol Chem. 2007 Jun 27;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17599915 17599915]
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NMR structural analysis of cadmium sensing by winged helix repressor CmtR., Banci L, Bertini I, Cantini F, Ciofi-Baffoni S, Cavet JS, Dennison C, Graham AI, Harvie DR, Robinson NJ, J Biol Chem. 2007 Oct 12;282(41):30181-8. Epub 2007 Jun 27. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17599915 17599915]
[[Category: Mycobacterium tuberculosis]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Single protein]]
[[Category: Single protein]]
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[[Category: Bertini, I.]]
[[Category: Bertini, I.]]
[[Category: Cantini, F.]]
[[Category: Cantini, F.]]
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[[Category: Cavet, J.S.]]
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[[Category: Cavet, J S.]]
[[Category: Ciofi-Baffoni, S.]]
[[Category: Ciofi-Baffoni, S.]]
[[Category: Dennison, C.]]
[[Category: Dennison, C.]]
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[[Category: Graham, A.I.]]
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[[Category: Graham, A I.]]
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[[Category: Harvie, D.R.]]
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[[Category: Harvie, D R.]]
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[[Category: Robinson, N.J.]]
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[[Category: Robinson, N J.]]
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[[Category: SPINE, Structural.Proteomics.in.Europe.]]
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[[Category: SPINE, Structural Proteomics in Europe.]]
[[Category: CD]]
[[Category: CD]]
[[Category: cadmium]]
[[Category: cadmium]]
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[[Category: transcriptional repressor]]
[[Category: transcriptional repressor]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 12:32:15 2008''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:05:35 2008''

Revision as of 16:05, 21 February 2008


2jsc

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NMR structure of the cadmium metal-sensor CMTR from Mycobacterium tuberculosis

Overview

CmtR from Mycobacterium tuberculosis is a winged helical DNA-binding repressor of the ArsR-SmtB metal-sensing family that senses cadmium and lead. Cadmium-CmtR is a dimer with the metal bound to Cys-102 from the C-terminal region of one subunit and two Cys associated with helix alphaR from the other subunit, forming a symmetrical pair of cadmium-binding sites. This is a significant novelty in the ArsR-SmtB family. The structure of the dimer could be solved at 312 K. The apoprotein at the same temperature is still a dimer, but it experiences a large conformational exchange at the dimer interface and within each monomer. This is monitored by an overall decrease of the number of nuclear Overhauser effects and by an increase of H(2)O-D(2)O exchange rates, especially at the dimeric interface, in the apo form with respect to the cadmium-bound state. The C-terminal tail region is completely unstructured in both apo and cadmium forms but becomes less mobile in the cadmium-bound protein due to the recruitment of Cys-102 as a metal-ligand. DNA binds to the apo dimer with a ratio 1:3 at millimolar concentration. Addition of cadmium to the apo-CmtR-DNA complex causes DNA detachment, restoring the NMR spectrum of free cadmium-CmtR. Cadmium binding across the dimer interface impairs DNA association by excluding the apo-conformers suited to bind DNA.

About this Structure

2JSC is a Single protein structure of sequence from Mycobacterium tuberculosis with as ligand. Full crystallographic information is available from OCA.

Reference

NMR structural analysis of cadmium sensing by winged helix repressor CmtR., Banci L, Bertini I, Cantini F, Ciofi-Baffoni S, Cavet JS, Dennison C, Graham AI, Harvie DR, Robinson NJ, J Biol Chem. 2007 Oct 12;282(41):30181-8. Epub 2007 Jun 27. PMID:17599915

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