Fatty Acid Synthesis and Regulation
Fatty acids are the building blocks of diverse membrane lipids and therefore are essential for the viability of bacterial cells. Fatty acids are energetically expensive to produce, and their production is highly controlled at the transcriptional and posttranscriptional level. Biosynthesis of fatty acids is catalyzed in most bacteria by a group of highly conserved proteins known as the type II fatty acid synthase (FAS II) system. This system was characterized in Escherichia coli, and a similar set of enzymes is present in different bacteria. Knowledge of biochemical regulation of fatty acid biosynthesis is inferred from studies in E. coli. During biosynthesis, fatty acids are esterified to the phosphopantetheine prosthetic group of the small acyl carrier protein (ACP). Long-chain acyl-ACPs, the end product of the pathway, exert feedback regulation over different key enzymes. There is a diversity of systems used for transcriptional regulation of fatty acid biosynthesis. Transcriptional regulation of fatty acid biosynthesis has been studied mainly in three model organisms, the Gram-negative E. coli and the Gram-positive organisms Bacillus subtilis and Streptococcus pneumoniae. The effector molecules that modulate activity of transcription factors involved in lipid biosynthesis are either substrates (malonyl-CoA) or final products (long-chain acyl-ACPs) of fatty acid biosynthesis. Long-chain acyl-CoAs, which are usually formed from exogenous fatty acids, are effectors of transcription factors that coordinate de novo biosynthesis with availability of fatty acids in the environment.
Work on IML-L’s lab was funded by Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM; PAPIIT IN202616). Work on MJS’s lab was funded by ERDF-cofinanced grant BIO2013-42801-P from the Spanish Ministry for Economy and Competitiveness. We thank Angeles Moreno-Ocampo and José Espíritu Salazar for skillful technical assistance.
- Bergler H, Fuchsbichler S, Högenauer G, Turnowsky F (1996) The enoyl-[acyl-carrier-protein] reductase (FabI) of Escherichia coli, which catalyzes a key regulatory step in fatty acid biosynthesis, accepts NADH and NADPH as cofactors and is inhibited by palmitoyl-CoA. Eur J Biochem 242(3):689–694CrossRefGoogle Scholar