The three-dimensional structure of the biotin carboxylase-biotin carboxyl carrier protein complex of E. coli acetyl-CoA carboxylase
Acetyl-coenzyme A (acetyl-CoA) carboxylase is a biotin-dependent, multifunctional enzyme that catalyzes the regulated step in fatty acid synthesis. The Escherichia coli enzyme is composed of a homodimeric biotin carboxylase (BC), biotinylated biotin carboxyl carrier protein (BCCP), and an α2β2 heterotetrameric carboxyltransferase. This enzyme complex catalyzes two half-reactions to form malonyl-coenzyme A. BC and BCCP participate in the first half-reaction, whereas carboxyltransferase and BCCP are involved in the second. Three-dimensional structures have been reported for the individual subunits; however, the structural basis for how BCCP reacts with the carboxylase or transferase is unknown. Therefore, we report here the crystal structure of E. coli BCCP complexed with BC to a resolution of 2.49 Å. The protein-protein complex shows a unique quaternary structure and two distinct interfaces for each BCCP monomer. These BCCP binding sites are unique compared to phylogenetically related biotin-dependent carboxylases and therefore provide novel targets for developing antibiotics against bacterial acetyl-CoA carboxylase. © 2013 Elsevier Ltd.
Publication Source (Journal or Book title)
Broussard, T., Kobe, M., Pakhomova, S., Neau, D., Price, A., Champion, T., & Waldrop, G. (2013). The three-dimensional structure of the biotin carboxylase-biotin carboxyl carrier protein complex of E. coli acetyl-CoA carboxylase. Structure, 21 (4), 650-657. https://doi.org/10.1016/j.str.2013.02.001