Cloning and sequencing of a cDNA for human mitochondrial ubiquinone-binding protein of complex III.
The ubiquinone-binding protein (QP-C) is a nuclear-encoded component of ubiquinol-cytochrome c oxidoreductase in the mitochondrial respiratory chain and plays an important role in electron transfer as a ubiquinone-QP-C complex. We obtained a partial cDNA for rat liver QP-C by screening a lambda gt11 rat liver cDNA library using antiserum directed against bovine heart QP-C. Using this cDNA as a probe, a cDNA clone was isolated from a human fibroblast cDNA library by colony hybridization. The total length of the cloned cDNA was 518 base pairs with an open reading frame of 333 base pairs. The 111-amino acid sequence deduced from the nucleotide sequence of the cDNA is 85% homologous to that of bovine QP-C and contains only a single additional amino-terminal methionine. This implies that the human QP-C is synthesized without a presequence which is required for import of most nuclear-encoded mitochondrial proteins into mitochondria.
Suzuki
H
H
Department of Biomedical Chemistry, Faculty of Medicine, University of Nagoya, Japan.
Hosokawa
Y
Y
Toda
H
H
Nishikimi
M
M
Ozawa
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002417:Cattle; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D005347:Fibroblasts / Q000032:analysis; D006801:Humans; D008928:Mitochondria / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011487:Protein Conformation; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014451:Ubiquinone
D002352:Carrier Proteins; C027208:ubiquinone-binding proteins; D014451:Ubiquinone; D004247:DNA