Characterization and expression of a cDNA specifying subunit VIIc of bovine cytochrome c oxidase.
We have isolated a cDNA that encodes subunit VIIc of bovine cytochrome c oxidase (COX VIIc). The 325-bp cDNA contains sequences encoding the mature 47-amino acid (aa) polypeptide and a 16-aa presequence. The deduced aa sequence of the processed polypeptide is identical to that of the heart protein determined by aa sequencing. Northern-blot analysis reveals a single 525-nucleotide (nt) transcript in all tissues examined, whose levels vary with the corresponding respiratory activities in different tissues; thus, no evidence for isoforms of COX VIIc is seen in adult tissues. Southern-blot analysis of bovine genomic DNA digested with three different restriction enzymes reveals several bands that hybridize with the cDNA. We present here the sequence of one genomic region that contains a processed gene encoding COX VIIc. The genomic and cDNA nt sequences are 99% identical throughout the 189-bp open reading frame; the deduced aa sequences are identical. The sequence of the genomic clone suggests that the cDNA terminates prematurely at an EcoRI site in the 3'-untranslated region. We have compared COX VIIc cDNAs from cow, human and mouse, and find the presequence similarity among them to be 100% at the aa level.
Aqua
M S
MS
Department of Molecular Biology and Genetics, Wayne State University School of Medicine, Detroit, MI 48201.
Bachman
N J
NJ
Lomax
M I
MI
Grossman
L I
LI
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D015139:Blotting, Southern; D002417:Cattle; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA; D003576:Electron Transport Complex IV / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
D004247:DNA; D003576:Electron Transport Complex IV; D015719:Single-Strand Specific DNA and RNA Endonucleases