In enzymology, a propionyl-CoA C2-trimethyltridecanoyltransferase (EC 2.3.1.154) is an enzyme that catalyzes the chemical reaction

4,8,12-trimethyltridecanoyl-CoA + propanoyl-CoA ${\displaystyle \rightleftharpoons }$ 3-oxopristanoyl-CoA + CoA

Thus, the two substrates of this enzyme are 4,8,12-trimethyltridecanoyl-CoA and propanoyl-CoA, whereas its two products are 3-oxopristanoyl-CoA and CoA.

This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is 4,8,12-trimethyltridecanoyl-CoA:propanoyl-CoA C2-4,8,12-trimethyltridecanoyltransferase. Other names in common use include 3-oxopristanoyl-CoA hydrolase, 3-oxopristanoyl-CoA thiolase, peroxisome sterol carrier protein thiolase, sterol carrier protein, oxopristanoyl-CoA thiolase, peroxisomal 3-oxoacyl coenzyme A thiolase, SCPx, 4,8,12-trimethyltridecanoyl-CoA:propanoyl-CoA, and 2-C-4,8,12-trimethyltridecanoyltransferase.

• Seedorf U, Brysch P, Engel T, Schrage K, Assmann G (1994). "Sterol carrier protein X is peroxisomal 3-oxoacyl coenzyme A thiolase with intrinsic sterol carrier and lipid transfer activity". J. Biol. Chem. 269 (33): 21277–83. PMID 8063752.
• Wanders RJ, Denis S, Wouters F, Wirtz KW, Seedorf U (1997). "Sterol carrier protein X (SCPx) is a peroxisomal branched-chain beta-ketothiolase specifically reacting with 3-oxo-pristanoyl-CoA: a new, unique role for SCPx in branched-chain fatty acid metabolism in peroxisomes" (PDF). Biochem. Biophys. Res. Commun. 236 (3): 565–569. doi:10.1006/bbrc.1997.7007. PMID 9245689.