Transcriptional regulator in fatty acid degradation. Represses transcription of genes required for fatty acid transport and beta-oxidation, including acdA, fadA, fadB, fadE, fadF, fadG, fadH, fadM, fadN, lcfA and lcfB. Binding of FadR to DNA is specifically inhibited by long chain fatty acyl-CoA compounds of 14-20 carbon atoms in length. Homodimer. Binds to DNA.