The stoichiometry of yeast V1-ATPase peripheral stalk subunits E and G was determined by two independent approaches using mass spectrometry (MS). First, the subunit ratio was inferred from measuring the molecular mass of the intact V1-ATPase complex, and each of the individual protein components, using native electrospray ionization-mass spectrometry (ESI-MS). The major observed intact complex had a mass of 593,600 Da, with minor components displaying masses of 553,550 Da and 428,300 Da, respectively. Second, defined amounts of V1-ATPase purified from yeast grown on 14N containing media were titrated with defined amounts of 15N labeled E and G subunits as internal standards. Following protease digestion of subunit bands, 14N and 15N containing peptide pairs were used for quantification of subunit stoichiometry using MALDI-TOF MS. Results from both approaches are in excellent agreement and reveal that the subunit composition of yeast V1-ATPase is A3B3DE3FG3H.
|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||Annotation Extension||Reference|
|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||Assay||Construct||Conditions||Strain Background||Reference|