3E6C: Cprk Ocpa Dna Complex

Certain bacteria are able to conserve energy via the reductive dehalogenation of halo-organic compounds in a respiration-type metabolism. The transcriptional regulator CprK from Desulfitobacterium spp. induces expression of halorespiratory genes upon binding of o-chlorophenol ligands and is reversibly inactivated by oxygen through disulphide bond formation. We report crystal structures of D. hafniense CprK in the ligand-free (both oxidation states), ligand-bound (reduced) and DNA-bound states, making it the first member of the widespread CRP-FNR superfamily for which a complete structural description of both redox-dependent and allosteric molecular rearrangements is available. In conjunction with kinetic and thermodynamic ligand binding studies, we provide a model for the allosteric mechanisms underpinning transcriptional control. Amino acids that play a key role in this mechanism are not conserved in functionally distinct CRP-FNR members. This suggests that, despite significant structural homology, distinct allosteric mechanisms are used, enabling this protein family to control a very wide range of processes.
PDB ID: 3E6CDownload
MMDB ID: 67064
PDB Deposition Date: 2008/8/15
Updated in MMDB: 2008/12
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Desulfitobacterium hafniense DCB-2
Similar Structures:
Biological Unit for 3E6C: hexameric; determined by author and by software (PISA)
Molecular Components in 3E6C
Label Count Molecule
Proteins (2 molecules)
Cyclic Nucleotide-binding Protein
Molecule annotation
Nucleotides(2 molecules)
DNA (5'- D(p*dgp*dcp*dap*dtp*dtp*dap*dap*dcp*dap*dtp*dgp*dcp*dc)-3')
Molecule annotation
DNA (5'- D(p*dgp*dgp*dcp*dap*dtp*dgp*dtp*dtp*dap*dap*dtp*dgp*dc)-3')
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB