GTP-specific succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of GTP and thus represents the only step of substrate-level phosphorylation in the TCA. The beta subunit provides nucleotide specificity of the enzyme and binds the substrate succinate, while the binding sites for coenzyme A and phosphate are found in the alpha subunit.
Subcellular locations: Mitochondrion
Mainly expressed in liver, kidney, heart, spleen and skeletal muscle. Also found in intestine and colon, and in low amounts in lung, brain, prostate, testis and ovary.