Modeling the Negative Feedback Mechanism in the Enzyme Carboxyltransferase

The enzyme acetyl-CoA carboxylase catalyzes the first committed step in fatty acid synthesis in all organisms. The E. coli form of the carboxyltransferase subunit was recently found to regulate its own activity and expression by binding its own mRNA. By binding acetyl-CoA or the mRNA encoding its own subunits, Carboxyltransferase is able to sense the metabolic state of the cell and attenuate its own translation and enzymatic activity using a negative feedback mechanism. In this paper, this network of interactions is modeled mathematically using mass action kinetics. Numerical simulations of the model show agreement with experimental results.