Molecular basis of halorespiration control by CprK, a CRP-FNR type transcriptional regulator.
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.
Levy
Colin
C
Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester M1 7DN, UK.
Pike
Katharine
K
Heyes
Derren J
DJ
Joyce
M Gordon
MG
Gabor
Krisztina
K
Smidt
Hauke
H
van der Oost
John
J
Leys
David
D
D000494:Allosteric Regulation; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002373:Cyclic AMP Receptor Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D045858:Desulfitobacterium / Q000737:chemistry* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D054879:Halogenation; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D010084:Oxidation-Reduction; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013816:Thermodynamics; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D004268:DNA-Binding Proteins; D007506:Iron-Sulfur Proteins; D008024:Ligands