Subunit Va of human and bovine cytochrome c oxidase is highly conserved.
We have isolated a full-length cDNA clone specifying the nuclear-encoded subunit Va of the human mitochondrial respiratory enzyme cytochrome c oxidase (COX; EC 1.9.3.1.). The deduced sequence of the polypeptide is 95% identical to that of the corresponding subunit of bovine COX, which makes it the most conserved polypeptide among the known bovine/human pairs of COX subunits. This polypeptide contains an N-terminal presequence which is rich in basic and hydroxylated residues, but differs from the deduced presequences of all other previously isolated COX subunits in that it also contains a negatively charged residue. We find no evidence of tissue-specific isoforms of subunit Va, as Northern analysis showed a single, identically-sized transcript in RNA from human muscle, liver, and brain, while coxVa cDNAs isolated from both endothelial and fetal muscle cDNA libraries had identical nucleotide sequences.
Rizzuto
R
R
H. Houston Merritt Clinical Research Center for Muscular Dystrophy and Related Disorders, Columbia University College of Physicians and Surgeons, New York, NY 10032.
Nakase
H
H
Zeviani
M
M
DiMauro
S
S
Schon
E A
EA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002417:Cattle; D003001:Cloning, Molecular; D003576:Electron Transport Complex IV / Q000235:genetics*; D005796:Genes; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011487:Protein Conformation; D015183:Restriction Mapping; D013045:Species Specificity; D014158:Transcription, Genetic
D046911:Macromolecular Substances; D003576:Electron Transport Complex IV