title: Complete amino acid sequence of the ubiquinone binding protein (QP-C), a protein similar to the 14,000-dalton subunit of the yeast ubiquinol-cytochrome c reductase complex.
abstract: The amino acid sequence of the ubiquinone binding protein (QP-C) in the cytochrome bc1 region of the mitochondrial electron transfer chain was determined by analysis of peptides obtained by cyanogen bromide cleavage and staphylococcal protease digestion of succinylated derivatives. It was found to consist of 110 amino acid residues and its amino terminus to be blocked by an acetyl group, as determined by mass spectrometry of the amino-terminal peptide and a comparison with peptides chemically synthesized on high-performance liquid chromatography. The molecular weight of this ubiquinone binding protein including the acetyl group was calculated to be 13,389. The predicted secondary structure of QP-C has alpha-helical content of about 50% and QP-C was classified as an "all-alpha" or "alpha + beta" protein. This is the first report describing the amino acid sequence of the ubiquinone binding protein. A comparison of this sequence with that of the 14-kDa subunit of the yeast ubiquinol-cytochrome c reductase complex from the nucleotide sequence showed these two sequences to be quite similar.
authors.forename: S
authors.initials: S
authors.lastname: Wakabayashi
authors.forename: T
authors.initials: T
authors.lastname: Takao
authors.forename: Y
authors.initials: Y
authors.lastname: Shimonishi
authors.forename: S
authors.initials: S
authors.lastname: Kuramitsu
authors.forename: H
authors.initials: H
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: T E
authors.initials: TE
authors.lastname: King
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification*; D002417:Cattle; D002918:Chymotrypsin; D003488:Cyanogen Bromide; D014450:Electron Transport Complex III; D009097:Multienzyme Complexes / Q000302:isolation & purification*; D009247:NADH, NADPH Oxidoreductases / Q000302:isolation & purification*; D010446:Peptide Fragments; D011487:Protein Conformation; D011808:Quinone Reductases / Q000302:isolation & purification*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D014357:Trypsin
chemical_list: D002352:Carrier Proteins; D009097:Multienzyme Complexes; D010446:Peptide Fragments; C027208:ubiquinone-binding proteins; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D002918:Chymotrypsin; D014357:Trypsin; D014450:Electron Transport Complex III; D003488:Cyanogen Bromide