Biostructural analysis of the metal-sensor domain of CnrX from Cupriavidus metallidurans CH34.
In Cupriavidus metallidurans CH34, the proteins CnrX, CnrY, and CnrH regulate the expression of the cnrCBA operon that codes for a cation-efflux pump involved in cobalt and nickel resistance. The periplasmic part of CnrX can be defined as the metal sensor in the signal transduction complex composed of the membrane-bound anti-sigma factor CnrY and the extra-cytoplasmic function sigma factor CnrH. A soluble form of CnrX was overproduced and purified. This protein behaves as a dimer in solution as judged from gel filtration, sedimentation velocity experiments, and NMR. Native crystals diffracting to 2.3 A using synchrotron radiation were obtained using the hanging-drop vapor-diffusion method. They belong to the primitive monoclinic space group P2(1), with unit cell parameters a = 31.87, b = 74.80, c = 93.67 A, beta = 90.107 degrees. NMR data and secondary structure prediction suggest that this protein is essentially formed by helices.
Pompidor
Guillaume
G
Laboratoire des Protéines Membranaires, Institut de Biologie Structurale-Jean-Pierre Ebel, UMR 5075 CNRS-CEA-UJF, 41, rue Jules Horowitz, 38027, Grenoble Cedex, France.
Girard
Eric
E
Maillard
Antoine
A
Ramella-Pairin
Stéphanie
S
Bersch
Beate
B
Kahn
Richard
R
Covès
Jacques
J
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003460:Crystallization; D049921:Cupriavidus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D009682:Magnetic Resonance Spectroscopy; D019216:Metals, Heavy / Q000494:pharmacology*; D008969:Molecular Sequence Data; D019897:Periplasm / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
D001426:Bacterial Proteins; D019216:Metals, Heavy