Structural Features of the Dynamic Interfaces in Fatty Acid Biosynthesis

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Fatty acid biosynthesis has emerged as the central pathway for hydrocarbon production of biofuel, and green algae have become an attractive host for efficient biomass production. While scientists have understood the basic mechanisms of de novo fatty acid synthase (FAS), recent studies have indicated that our understanding of the molecular events that organize and regulate this pathway are poorly understood; and engineering these pathways remains challenging. This project aims to carefully study the molecular regulation of the FAS pathway in bacteria and algae, with a goal toward enabling metabolic engineering this pathway for biofuel applications. The investigators have already demonstrated that the development of an alternative fuel source from microalgal biomass has created many significant opportunities for education and community outreach. With the potential to provide the requisite energy for continued human progress and development, algal biofuels will almost certainly play a major role in our energy future. As such, a significant aspect of this research aims to augment student and public awareness of the need for alternative energy sources and the positive impacts of the widespread adoption of algal biofuels. The basic pathway and mechanisms of FAS are included in most introductory biochemistry textbooks, and much has been known about the organization of this pathway for several decades. However, attempts to engineer FAS in various organisms have been met with unpredictable results that highlight many gaps in our understanding. Recent evidence has demonstrated that protein-protein interactions of the acyl carrier protein (ACP) and FAS enzymes play fundamental roles regulating the reactivity and timing of FAS processing, and these interactions are key to the successful engineering of these pathways. This proposal aims to systematically characterize the protein-protein interactions within the FAS of the bacterium Escherichia coli. To study these specific interactions, the investigators have developed a toolkit that includes chemo-enzymatic ACP-substrate conjugation coupled with solution-phase protein NMR to elucidate the specific amino acid residues involved in these interactions. These tools will be applied to study heterologous combinations of FAS enzymes for metabolic engineering of FAS from E. coli and the green alga Chlamydomonas reinhardtii. The proposed research will be accompanied by the development of a new Masters of Science program targeted to train the future biofuels scientists that builds upon a certificate program begun by the investigators.