The Structural Basis of Acyl Coenzyme A-Dependent Regulation of the Transcription Factor Fadr
Van Aalten, D.M.F., Dirusso, C.C., Knudsen, J.(2001) EMBO J 20: 2041
- PubMed: 11296236
- DOI: https://doi.org/10.1093/emboj/20.8.2041
- Primary Citation of Related Structures:
1H9G, 1H9T - PubMed Abstract:
FadR is an acyl-CoA-responsive transcription factor, regulating fatty acid biosynthetic and degradation genes in Escherichia coli. The apo-protein binds DNA as a homodimer, an interaction that is disrupted by binding of acyl-COA: The recently described structure of apo-FadR shows a DNA binding domain coupled to an acyl-CoA binding domain with a novel fold, but does not explain how binding of the acyl-CoA effector molecule > 30 A away from the DNA binding site affects transcriptional regulation. Here, we describe the structures of the FadR-operator and FadR- myristoyl-CoA binary complexes. The FadR-DNA complex reveals a novel winged helix-turn-helix protein-DNA interaction, involving sequence-specific contacts from the wing to the minor groove. Binding of acyl-CoA results in dramatic conformational changes throughout the protein, with backbone shifts up to 4.5 A. The net effect is a rearrangement of the DNA binding domains in the dimer, resulting in a change of 7.2 A in separation of the DNA recognition helices and the loss of DNA binding, revealing the molecular basis of acyl-CoA-responsive regulation.
Organizational Affiliation:
Wellcome Trust Biocentre, Division of Biological Chemistry and Molecular Microbiology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK. dava@davapc1.bioch.dundee.ac.uk