Nucleotide sequence for cDNA of bovine mitochondrial ATP-dependent protease and determination of N-terminus of the mature enzyme from the adrenal cortex

• Published in: DNA sequence 2005-12, Vol.16 (6), p.474-478
• Main Authors: Yamamoto, Misa, Hiroi, Tomoko, Kohno, Hiroyuki, Yamamoto, Yoshimi, Hara, Masayuki, Tanaka, Tatehiko, Mamba, Kouichi, Watabe, Shoji
• Format: Article
• Language: English
• Subjects: Adrenal Cortex - enzymology; Amino Acid Sequence; Animals; ATP-Dependent Proteases - chemistry; ATP-Dependent Proteases - classification; ATP-Dependent Proteases - genetics; Base Sequence; Cattle; DNA, Complementary - genetics; Escherichia coli; Humans; Mass Spectrometry; Mitochondria - enzymology; Molecular Sequence Data; Peptide Fragments - chemistry; Sequence Homology, Amino Acid
• ISSN: 1042-5179; 1029-2365
• DOI: 10.1080/10425170500289233

We have determined the cDNA sequence encoding bovine mitochondrial ATP-dependent Lon protease. Since the 5′-end region of the cDNA was highly GC-rich and thus could not be amplified by the 5′-RACE method, a genomic DNA fragment containing an in-frame ATG was isolated and sequenced. The translated amino acid sequence contained 961 amino acids with a calculated molecular weight 106,665. Sequence similarities of the bovine enzyme to human and E. coli orthologs were 92 and 27%, respectively. The N-terminal amino acid sequence seemed to be a mitochondrial targeting signal. To determine the cleavage site of the signal sequence we analyzed the mature enzyme purified from bovine adrenocortical mitochondria. Analysis of CNBr-digested peptides revealed that the N-terminus was heterogeneous. We suggest that nonspecific aminopeptidase might remove several amino acids from the N-terminus after mitochondrial processing peptidase has cleaved Gly67-Leu68 or Leu68-Trp69.