The FadR.DNA complex. Transcriptional control of fatty acid metabolism in Escherichia coli.
In Escherichia coli, the expression of fatty acid metabolic genes is controlled by the transcription factor, FadR. The affinity of FadR for DNA is controlled by long chain acyl-CoA molecules, which bind to the protein and modulate gene expression. The crystal structure of FadR reveals a two domain dimeric molecule where the N-terminal domains bind DNA, and the C-terminal domains bind acyl-CoA. The DNA binding domain has a winged-helix motif, and the C-terminal domain resembles the sensor domain of the Tet repressor. The FadR.DNA complex reveals how the protein interacts with DNA and specifically recognizes a palindromic sequence. Structural and functional similarities to the Tet repressor and the BmrR transcription factors suggest how the binding of the acyl-CoA effector molecule to the C-terminal domain may affect the DNA binding affinity of the N-terminal domain. We suggest that the binding of acyl-CoA disrupts a buried network of charged and polar residues in the C-terminal domain, and the resulting conformational change is transmitted to the N-terminal domain via a domain-spanning alpha-helix.
Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
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D000214:Acyl Coenzyme A / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
D000214:Acyl Coenzyme A; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C057119:FadR protein, Bacteria; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors