Biostructural analysis of the metal-sensor domain of CnrX from Cupriavidus metallidurans CH34

Guillaume Pompidor (1) , Eric Girard (1) , Antoine P. Maillard (2) , Stéphanie Ramella-Pairin , Beate Bersch (1) , Richard Kahn (1) , Jacques Covès (1)

1 IBS - UMR 5075 - Institut de biologie structurale
2 PBRC - Pathogenèse bactérienne et réponses cellulaires

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.

Domaines: Sciences du Vivant [q-bio]

Guillaume Pompidor, Eric Girard, Antoine P. Maillard, Stéphanie Ramella-Pairin, Beate Bersch, et al.. Biostructural analysis of the metal-sensor domain of CnrX from Cupriavidus metallidurans CH34. Antonie van Leeuwenhoek, 2009, 96 (2), pp.141-148. ⟨10.1007/s10482-008-9283-6⟩. ⟨hal-02332931⟩