FadR Binding with Coenzyme A

Coenzyme A binding with the FadR monomer

When there are long chain fatty acids present in eschericia coli they are converted into long chain Acyl Coenzyme A thioesters. These long chain fatty acids bind to FadR in the carboxyl terminus of the protein. The C-terminal starts at residue 79 and contains seven alpha helices which are packed together in a tight bundle. Each Helix is arranged anti parallel from its neighbor except for the first and last helix in the bundle, which stack in a parallel manor. Coenzyme A will embed itself deep inside a large cavity. The residues in this cavity form a lattice connecting the helices in the C-terminal. It is theorized that when acyl coenzyme A thioesters bind to FadR this lattice is disrupted casing a large conformational change in the N-terminal of the protein. This change allows the DNA to become free and transcribe the genes that metabolize fatty acids. (A view of the conformational change undergone by FadR is shown at this website)

This view shows the deep embedment of the coenzyme A into the C-terminal of the FadR monomer.