MetaCyc Enzyme: succinyl-CoA:3-ketoacid-coenzyme A transferase 1, mitochondrial

Gene: OXCT1 Accession Number: HS01447 (MetaCyc)

Synonyms: OXCT, SCOT, 3-oxoacid-CoA transferase 1, Scot-S, somatic-type succinyl CoA:3-oxoacid CoA-transferase

Species: Homo sapiens

The mitochondrial succinyl-CoA:3-ketoacid-coenzyme A transferase 1 (SCOT) activity is the main determinant of the ketolytic capacity of tissues and is not present in liver, so that organ can not use ketone bodies for fuel, but instead exports them to blood for distribution to peripheral tissues [Fukao97]. The enzyme is active as a homodimer in the mitochondrial matrix and activates acetoacetate to acetoacetate-CoA for energy production by terminal oxidative phosphorylation.

Hereditary SCOT deficiency, including mutations at amino acids 219, 221, 324 and S283X, results in severe episodes of ketoacidosis [KassovskaBratin96][Fukao00].

Citations: [Song98a]

Locations: mitochondrion

Map Position: [42,830,638 <- 42,971,034] (23.56 centisomes)

Unification Links: ArrayExpress:P55809 , Entrez-gene:5019 , PhosphoSite:P55809 , PhylomeDB:P55809 , Pride:P55809 , Protein Model Portal:P55809 , SMR:P55809 , String:9606.ENSP00000196371 , UniProt:P55809

Relationship Links: InterPro:IN-FAMILY:IPR004163 , InterPro:IN-FAMILY:IPR004164 , InterPro:IN-FAMILY:IPR004165 , InterPro:IN-FAMILY:IPR012791 , InterPro:IN-FAMILY:IPR012792 , InterPro:IN-FAMILY:IPR014388 , Panther:IN-FAMILY:PTHR13707 , PDB:Structure:3DLX , Pfam:IN-FAMILY:PF01144 , Prosite:IN-FAMILY:PS01273 , Prosite:IN-FAMILY:PS01274 , Smart:IN-FAMILY:SM00882

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0006104 - succinyl-CoA metabolic process
GO:0008152 - metabolic process
Molecular Function: GO:0008260 - 3-oxoacid CoA-transferase activity
GO:0016740 - transferase activity
Cellular Component: GO:0005739 - mitochondrion

Enzymatic reaction of: acetoacetate CoA-transferase (succinyl-CoA:3-ketoacid-coenzyme A transferase 1, mitochondrial)

succinyl-CoA + acetoacetate <=> succinate + acetoacetyl-CoA

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

This reaction is reversible.

In Pathways: ketolysis


Schematic showing introns, exons and/or isoforms of OXCT1


Fukao00: Fukao T, Mitchell GA, Song XQ, Nakamura H, Kassovska-Bratinova S, Orii KE, Wraith JE, Besley G, Wanders RJ, Niezen-Koning KE, Berry GT, Palmieri M, Kondo N (2000). "Succinyl-CoA:3-ketoacid CoA transferase (SCOT): cloning of the human SCOT gene, tertiary structural modeling of the human SCOT monomer, and characterization of three pathogenic mutations." Genomics 68(2);144-51. PMID: 10964512

Fukao97: Fukao T, Song XQ, Mitchell GA, Yamaguchi S, Sukegawa K, Orii T, Kondo N (1997). "Enzymes of ketone body utilization in human tissues: protein and messenger RNA levels of succinyl-coenzyme A (CoA):3-ketoacid CoA transferase and mitochondrial and cytosolic acetoacetyl-CoA thiolases." Pediatr Res 42(4);498-502. PMID: 9380443

Hersh67: Hersh LB, Jencks WP (1967). "Isolation of an enzyme-coenzyme A intermediate from succinyl coenzyme A-acetoacetate coenzyme A transferase." J Biol Chem 242(2);339-40. PMID: 6016620

KassovskaBratin96: Kassovska-Bratinova S, Fukao T, Song XQ, Duncan AM, Chen HS, Robert MF, Perez-Cerda C, Ugarte M, Chartrand C, Vobecky S, Kondo N, Mitchell GA (1996). "Succinyl CoA: 3-oxoacid CoA transferase (SCOT): human cDNA cloning, human chromosomal mapping to 5p13, and mutation detection in a SCOT-deficient patient." Am J Hum Genet 59(3);519-28. PMID: 8751852

Song98a: Song XQ, Fukao T, Watanabe H, Shintaku H, Hirayama K, Kassovska-Bratinova S, Kondo N, Mitchell GA (1998). "Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency: two pathogenic mutations, V133E and C456F, in Japanese siblings." Hum Mutat 12(2);83-8. PMID: 9671268

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Mon Oct 5, 2015, biocyc14.