SNAP output for PDB entry 3e6c [SNAP web server]

PDB-id

3e6c; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription regulation-DNA

Method

X-ray (1.8 Å)

Summary

Cprk ocpa DNA complex

Reference

Levy C, Pike K, Heyes DJ, Joyce MG, Gabor K, Smidt H, van der Oost J, Leys D (2008): "Molecular basis of halorespiration control by CprK, a CRP-FNR type transcriptional regulator." Mol.Microbiol., 70, 151-167. doi: 10.1111/j.1365-2958.2008.06399.x.

Abstract

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.