Succinyl-CoA

Succinyl-coenzyme A, abbreviated as succinyl-CoA or SucCoA, is a thioester of succinic acid and coenzyme A.

Fate
It is converted into succinate through the hydrolytic release of coenzyme A by succinyl-CoA synthetase (succinate thiokinase).

Another fate of succinyl-CoA is porphyrin synthesis, where succinyl-CoA and glycine are combined by ALA synthase to form δ-aminolevulinic acid (dALA). This process is the committed step in the biosynthesis of porfobilinogen and thus hemoglobin.

Formation
Succinyl CoA can be formed from methylmalonyl CoA through the utilization of deoxyadenosyl-B12 (deoxyadenosylcobalamin) by the enzyme methylmalonyl-CoA mutase. This reaction, which requires vitamin B12 as a cofactor, is important in the catabolism of some branched-chain amino acids as well as odd-chain fatty acids.