NCA3, a nuclear gene involved in the mitochondrial expression of subunits 6 and 8 of the Fo-F1 ATP synthase of S. cerevisiae

Curr Genet. 1995 Apr;27(5):409-16. doi: 10.1007/BF00311209.


Respiratory-competent nuclear mutants have been isolated which presented a cryosensitive phenotype on a non-fermentative carbon source, due to a dysfunctioning of the mitochondrial F1-Fo ATP synthase which results from a relative defect in subunits 6 and 8 of the Fo sector. Both proteins are mtDNA-encoded, but the defect is due to the simultaneous presence of a mutation in two unlinked nuclear genes (NCA2 and NCA3, for Nuclear Control of ATPase) promoting a modification of the expression of the ATP8-ATP6 co-transcript (formerly denoted AAP1-OLI2). This co-transcript matures at a unique site to give two cotranscripts of 5.2 and 4.6 kb in length: in the mutant, the 5.2-kb co-transcript was greatly lowered. NCA3 was isolated from a wild-type yeast genomic library by genetic complementation. The level of the 5.2-kb transcript, like the synthesis of subunits 6 and 8, was partly restored in the transformed strain. A 1011-nucleotide ORF was identified that encodes an hydrophilic protein of 35417 Da. Disruption of chromosomal DNA within the reading frame promoted a dramatic decrease of the 5.2-kb mRNA but did not abolish the respiratory competence of a wild-type strain. NCA3 is located on chromosome IV and produces a single 1780-b transcript.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • Genes, Fungal
  • Mitochondria / enzymology*
  • Mitochondria / genetics*
  • Mitochondria / metabolism
  • Molecular Sequence Data
  • Mutation
  • Protein Biosynthesis
  • Proton-Translocating ATPases / genetics*
  • RNA, Messenger
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics*
  • Sequence Analysis, DNA
  • Transcription, Genetic


  • RNA, Messenger
  • Proton-Translocating ATPases

Associated data

  • GENBANK/L20786