The F1 component of mitochondrial ATP synthase is an oligomeric assembly of five different subunits: a, b, g, d, e. In terms of mass, the bulk of the structure (~ 90%) is provided by the a and b subunits, which form an (ab)3 hexamer with adenine nucleotide binding sites at the a/b interfaces. We presently report ultrastructural and immunocytochemical analyses of yeast mutants that are unable to form the a3b3 oligomer, either because the a subunit or the b subunit is missing, or because the cells are deficient for proteins that mediate F1 assembly (e.g Atp11p, Atp12p, or Fmc1p). The F1 a and b subunits of such mutant strains are detected within large, electron-dense particles in the mitochondrial matrix. The composition of the aggregated species is principally full-length F1 a and/or b subunit protein that has been processed to remove the amino-terminal targeting peptide. To our knowledge this is the first demonstration of mitochondrial inclusion bodies that are formed largely of one particular protein species. We also show that yeast mutants lacking the a3b3 oligomer are devoid of mitochondrial cristae and are severely deficient for respiratory complexes III and IV. These observations are in accord with other studies in the literature that have pointed to a central role for the ATP synthase in biogenesis of the mitochondrial inner membrane.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|