ATP-specific succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of ATP and thus represents the only step of substrate-level phosphorylation in the TCA (PubMed:15877282, PubMed:34492704, PubMed:40108300). 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 (By similarity). Also able to act as an AT

Mitochondrion

Mitochondrial DNA depletion syndrome 5

A disorder due to mitochondrial dysfunction. It is characterized by infantile onset of hypotonia, neurologic deterioration, a hyperkinetic-dystonic movement disorder, external ophthalmoplegia, deafness, variable renal tubular dysfunction, and mild methylmalonic aciduria in some patients.

Plays a pivotal role in cell survival by repairing damaged DNA in a p53/TP53-dependent manner. Supplies deoxyribonucleotides for DNA repair in cells arrested at G1 or G2. Contains an iron-tyrosyl free radical center required for catalysis. Forms an active ribonucleotide reductase (RNR) complex with RRM1 which is expressed both in resting and proliferating cells in response to DNA damage

CytoplasmNucleus

Mitochondrial DNA depletion syndrome 8A

A disorder due to mitochondrial dysfunction characterized by various combinations of neonatal hypotonia, neurological deterioration, respiratory distress, lactic acidosis, and renal tubulopathy.

Succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of either ATP or GTP and thus represents the only step of substrate-level phosphorylation in the TCA (PubMed:34492704, PubMed:40108300). The alpha subunit of the enzyme binds the substrates coenzyme A and phosphate, while succinate binding and specificity for either ATP or GTP is provided by different beta subunits (By similarity). Also able to act as an itaconyl- and malyl-

Mitochondrion

Mitochondrial DNA depletion syndrome 9

A severe disorder due to mitochondrial dysfunction. It is characterized by infantile onset of hypotonia, lactic acidosis, severe psychomotor retardation, progressive neurologic deterioration, and excretion of methylmalonic acid.

Substrate-recognition component of the mitochondria-localized SCF-FBXL4 ubiquitin E3 ligase complex that plays a role in the restriction of mitophagy by controlling the degradation of BNIP3 and NIX mitophagy receptors (PubMed:36896912, PubMed:38992176). Rescues also mitochondrial injury through reverting hyperactivation of DRP1-mediated mitochondrial fission (By similarity)

CytoplasmNucleusMitochondrion outer membrane

Mitochondrial DNA depletion syndrome 13

An autosomal recessive disorder characterized by early infantile onset of encephalopathy, hypotonia, lactic acidosis, and severe global developmental delay. Cells derived from patient tissues show defects in mitochondrial oxidative phosphorylation and decreased mtDNA content.