Plays a crucial role in the peroxisomal oxidation of branched-chain fatty acids (PubMed:10706581). Catalyzes the last step of the peroxisomal beta-oxidation of branched chain fatty acids and the side chain of the bile acid intermediates di- and trihydroxycoprostanic acids (DHCA and THCA) (PubMed:10706581). Also active with medium and long straight chain 3-oxoacyl-CoAs. Stimulates the microsomal conversion of 7-dehydrocholesterol to cholesterol and transfers phosphatidylcholine and 7-dehydrocholesterol between membrances, in vitro (By similarity). Isoforms SCP2 and SCPx cooperate in peroxisomal oxidation of certain naturally occurring tetramethyl-branched fatty acyl-CoAs (By similarity). Mediates the transfer of all common phospholipids, cholesterol and gangliosides from the endoplasmic reticulum to the plasma membrane. May play a role in regulating steroidogenesis (PubMed:17157249, PubMed:8300590, PubMed:7642518). Stimulates the microsomal conversion of 7-dehydrocholesterol to cholesterol (By similarity). Also binds fatty acids and fatty acyl Coenzyme A (CoA) such as phytanoyl-CoA. Involved in the regulation phospholipid synthesis in endoplasmic reticulum enhancing the incorporation of exogenous fatty acid into glycerides. Seems to stimulate the rate-limiting step in phosphatidic acid formation mediated by GPAT3. Isoforms SCP2 and SCPx cooperate in peroxisomal oxidation of certain naturally occurring tetramethyl-branched fatty acyl-CoAs (By similarity). choloyl-CoA + propanoyl-CoA = 3alpha,7alpha,12alpha-trihydroxy-24-oxo-5beta-cholestan-26-oyl-CoA + CoA 4,8,12-trimethyltridecanoyl-CoA + propanoyl-CoA = 3-oxopristanoyl-CoA + CoA acetyl-CoA + an acyl-CoA = a 3-oxoacyl-CoA + CoA acetyl-CoA + hexanoyl-CoA = 3-oxooctanoyl-CoA + CoA acetyl-CoA + tetradecanoyl-CoA = 3-oxohexadecanoyl-CoA + CoA 3-oxohexadecanedioyl-CoA + CoA = acetyl-CoA + tetradecanedioyl-CoA propanoyl-CoA + tetradecanoyl-CoA = 3-oxo-2-methylhexadecanoyl-CoA + CoA acetyl-CoA + butanoyl-CoA = 3-oxohexanoyl-CoA + CoA acetyl-CoA + octanoyl-CoA = 3-oxodecanoyl-CoA + CoA acetyl-CoA + decanoyl-CoA = 3-oxododecanoyl-CoA + CoA acetyl-CoA + dodecanoyl-CoA = 3-oxotetradecanoyl-CoA + CoA acetyl-CoA + hexadecanoyl-CoA = 3-oxooctadecanoyl-CoA + CoA 3-oxo-(9Z-octadecenoyl)-CoA + CoA = (7Z)-hexadecenoyl-CoA + acetyl-CoA 7-dehydrocholesterol(in) = 7-dehydrocholesterol(out) 7-dehydrocholesterol(in) = 7-dehydrocholesterol(out) Interacts with PEX5; the interaction is essential for peroxisomal import. Liver, fibroblasts, and placenta. Up-regulated by 4-hydroxy-tamoxifen. preSCP2, a protein with a molecular mass of about 15 kDa, is processed into its mature form (SCP2) by proteolytic cleavage of a 20 residue leader sequence after translocation into peroxisomes. The disease is caused by variants affecting the gene represented in this entry. Expression at protein level is almost abolished in Zellweger syndrome. Cholesterol transfer from the endoplasmic reticulum to the plasma membrane was reduced in patient fibroblasts compared to controls. Contains a putative mitochondrial transit peptide at positions 1-20. Produced by alternative splicing. Produced by alternative splicing. Produced by alternative splicing. In the N-terminal section; belongs to the thiolase-like superfamily. Thiolase family. Truncated N-terminus.