Deglycosylated yeast invertase is irreversibly inactivated by conduritol B epoxide (CBE), an active-site-directed reagent. The inactivated enzyme contained 0.8 mol of CBE/mol of invertase monomer suggesting that the inactivation results from the modification of a single amino acid residue. Peptic digestion of [3H]CBE-labeled invertase followed by reverse phase column chromatography yielded two labeled peptides, both located at the amino-terminal end of the enzyme. Sequence analyses of these peptides revealed that Asp-23 is the modified residue. The role of Asp-23 in the catalytic process was investigated by changing it to Asn using site-directed mutagenesis of the SCU2 gene. The mutant enzyme was basically inactive, confirming a role for Asp-23 in the catalytic process.
|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|