Molecular cloning and nucleotide sequence of cDNA for mRNA of mitochondrial cytochrome P-450(SCC) of bovine adrenal cortex

摘要: We have isolated cDNA clones of the mRNA for cytochrome P-450(SCC), which catalyzes side-chain cleavage reaction cholesterol in bovine adrenal cortex mitochondria, by using synthetic oligonucleotides as probes. Sequence analysis cloned cDNAs enabled us to deduce primary structure precursor form consisted 520 amino acids and contained an extrapeptide 39 at NH2 terminus. The acid sequence from 40th 55th residue predicted completely coincided with NH2-terminal portion purified P-450(SCC). composition calculated showed excellent agreement that determined protein. molecule resembles those a few nuclear-encoded yeast mitochondrial proteins reported so far. Although P-450(SCC) is component comparison its other forms P-450 shows structurally more related microsomal P-450s than bacterial P-450, P-450cam. A homologous observed various also highly conserved molecule. Only two cysteinyl residues are present mature one located middle sequence, confirming function this fifth ligand heme.