Molecular cloning and nucleotide sequence of DNA of mitochondrial cytochrome P-450(11 beta) of bovine adrenal cortex.
cDNA clones of the mRNA for bovine adrenal cytochrome P-450(11 beta) were isolated. Sequence analysis of a 4 kb long cDNA revealed the primary structure of P-450(11 beta), which consisted of 503 amino acids (Mr: 57,924) and contained an extension peptide of 24 amino acids at the NH2-terminus of the mature P-450(11 beta). molecule. A bovine genomic DNA containing the 1st exon and its leader sequence of P-450(11 beta) gene was also isolated from a bovine gene library. Determination of the transcription initiation site by S1 nuclease analysis using the cloned genomic DNA confirmed that the methionine codon near the 5' side of the 4 kb long cDNA was the initiation codon. Comparisons of the primary structures among P-450(11 beta) and other forms of cytochrome P-450 including P-450(SCC) indicated that the two mitochondrial P-450s, P-450(11 beta) and P-450(SCC), were significantly different from microsomal forms of cytochrome P-450. The homology between P-450(11 beta) and P-450(SCC) was 36%, which is higher than the values between P-450(11 beta) and various microsomal P-450s. An alignment of P-450(11 beta) and P-450(SCC) to give maximum matching showed four highly conserved regions (C-1, C-2, C-3, and C-4). The homology values of these regions were 58-70%, considerably higher than the overall homology between these two mitochondrial P-450s. A putative heme binding site and a steroid binding site were located in the conserved regions. Hydropathy profiles of P-450(11 beta) and P-450(SCC) were very similar. A definite difference was noticed at the NH2-terminal portion between mitochondrial and microsomal types of P-450. Microsomal type of cytochrome P-450 had a hydrophobic sequence consisting of about 20 amino acids, whereas mitochondrial type had an extension peptide containing many positively changed amino acids.
Department of Biology, Faculty of Science, Kyushu University, Fukuoka.
K
K
Morohashi
H
H
Yoshioka
O
O
Gotoh
Y
Y
Okada
K
K
Yamamoto
T
T
Miyata
K
K
Sogawa
Y
Y
Fujii-Kuriyama
T
T
Omura
D000302:Adrenal Cortex / Q000201:enzymology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D004247:DNA / Q000032:analysis*; D003851:Deoxyribonucleases / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data
D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D003851:Deoxyribonucleases