2JSC

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

2JSC の概要

• エントリーDOI: 10.2210/pdb2jsc/pdb
• 分子名称: Transcriptional regulator Rv1994c/MT2050, CADMIUM ION (2 entities in total)
• 機能のキーワード: cadmium, transcriptional repressor, solution structure, structural genomics, structural proteomics in europe, spine, transcription
• 由来する生物種: Mycobacterium tuberculosis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 25243.68

構造登録者

Banci, L.,Bertini, I.,Cantini, F.,Ciofi-Baffoni, S.,Cavet, J.S.,Dennison, C.,Graham, A.I.,Harvie, D.R.,Robinson, N.J.,Structural Proteomics in Europe (SPINE) (登録日: 2007-07-02, 公開日: 2007-07-31, 最終更新日: 2023-12-20)

主引用文献

Banci, L.,Bertini, I.,Cantini, F.,Ciofi-Baffoni, S.,Cavet, J.S.,Dennison, C.,Graham, A.I.,Harvie, D.R.,Robinson, N.J.
NMR Structural Analysis of Cadmium Sensing by Winged Helix Repressor CmtR.
J.Biol.Chem., 282:30181-30188, 2007

PubMed Abstract: 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: 17599915
DOI: 10.1074/jbc.M701119200

実験手法

SOLUTION NMR