succinylCoArelated

Succinyl-CoA is a crucial intermediate molecule in cellular metabolism. It is a thioester of succinic acid and Coenzyme A. Succinyl-CoA plays a central role in both the citric acid cycle (also known as the Krebs cycle or TCA cycle) and in the breakdown of certain amino acids and fatty acids.

Within the citric acid cycle, succinyl-CoA is formed from alpha-ketoglutarate through the action of the alpha-ketoglutarate dehydrogenase complex. This conversion is a key step in the oxidative decarboxylation of carbohydrates. Subsequently, succinyl-CoA is converted to succinate by the enzyme succinyl-CoA synthetase, a reaction that also generates ATP (or GTP in some organisms) through substrate-level phosphorylation.

Beyond the citric acid cycle, succinyl-CoA is involved in the catabolism of specific amino acids like valine, isoleucine, methionine, and threonine. It also appears in the metabolism of some fatty acids and porphyrins, the precursors to heme. The interconnectedness of these pathways highlights the central importance of succinyl-CoA in energy production and biosynthesis. Its formation and subsequent metabolism are tightly regulated to meet the cell's metabolic demands.