Beta subunit of mitochondrial F1-ATPase from the fission yeast. Deduced sequence of the wild type protein and identification of a mutation that increases nucleotide binding.
The Schizosaccharomyces pombe nuclear gene, atp2, encoding the beta subunit of the mitochondrial ATP synthase, was sequenced and found to contain a 1575-bp open reading frame. Two adjacent transcription-initiation sites were found at positions 34 and 44 nucleotides upstream of the translation-initiation codon. The deduced polypeptide sequence was composed of 525 amino acid residues (molecular mass = 56875 Da). The mature polypeptide starts at residue 45 (molecular mass = 51,685 Da), indicating the presence of a presequence of 44 residues, presumably involved in mitochondrial targeting. The atp2 mutant B59-1 [Boutry, M. & Goffeau, A. (1982) Eur. J. Biochem. 125, 471-477] and its related revertant allele R4-3 [Jault, J. M., Di Pietro, A., Falson, P., Gautheron, D. C., Boutry, M. & Goffeau, A. (1989) Biochem. Biophys. Res. Commun. 158, 392-399] were also cloned and sequenced. A single nonsense mutation, CAG (Gln170)----TAG (stop) in mutant B59-1, became a missense mutation, TAG (stop)----TAC (Tyr) in revertant R4-3. Gln170 is located between the first and second elements belonging to the nucleotide-binding site. Its substitution by a tyrosine residue increases the enzyme affinity towards ADP, the amount of endogenous nucleotides and the apparent negative cooperativity for ATPase activity.
Falson
P
P
Unité de Biochimie Physiologique, Université Catholique de Louvain, Louvain-La-Neuve, Belgium.
Leterme
S
S
Capiau
C
C
Boutry
M
M
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005800:Genes, Fungal; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D006180:Proton-Translocating ATPases / Q000235:genetics*; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D014157:Transcription Factors; D006180:Proton-Translocating ATPases