MalonyyliCoA
Malonyl-CoA is the coenzyme A thioester of malonic acid and a central metabolite in lipid metabolism. It functions as the two-carbon donor in fatty acid synthesis, enabling the elongation of acyl chains via the fatty acid synthase (FAS) pathway. In many organisms, malonyl-CoA is formed from acetyl-CoA by the carboxylation reaction catalyzed by acetyl-CoA carboxylase (ACC), requiring ATP and biotin as a cofactor.
In animals, two ACC isoforms exist: ACC1 in the cytosol for lipogenesis and ACC2 associated with mitochondria
Regulation and degradation: ACC activity is modulated by phosphorylation (e.g., AMP-activated protein kinase inhibits ACC) and
In bacteria and plants, malonyl-CoA is used by type II FAS and by polyketide synthases as an