Linked Life Data

17599915

Source:http://linkedlifedata.com/resource/pubmed/id/17599915

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
2007-10-8
pubmed:databankReference
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30181-8
pubmed:meshHeading
pubmed-meshheading:17599915-Bacterial Proteins, pubmed-meshheading:17599915-Binding Sites, pubmed-meshheading:17599915-Cadmium, pubmed-meshheading:17599915-Cysteine, pubmed-meshheading:17599915-DNA, pubmed-meshheading:17599915-DNA-Binding Proteins, pubmed-meshheading:17599915-Dimerization, pubmed-meshheading:17599915-Helix-Turn-Helix Motifs, pubmed-meshheading:17599915-Magnetic Resonance Spectroscopy, pubmed-meshheading:17599915-Molecular Conformation, pubmed-meshheading:17599915-Mycobacterium tuberculosis, pubmed-meshheading:17599915-Nucleic Acid Conformation, pubmed-meshheading:17599915-Protein Binding, pubmed-meshheading:17599915-Protein Structure, Secondary, pubmed-meshheading:17599915-Protein Structure, Tertiary, pubmed-meshheading:17599915-Repressor Proteins, pubmed-meshheading:17599915-Temperature
pubmed:year
2007
pubmed:articleTitle
NMR structural analysis of cadmium sensing by winged helix repressor CmtR.
pubmed:affiliation
Department of Chemistry and Centro Risonanze Magnetiche, University of Florence, Via Luigi Sacconi 6, Florence 50019, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't