Proteasome Endopeptidase ComplexSubstrate SpecificityKineticsMolecular Sequence DataAmino Acid SequenceProteolysisUbiquitinBiodegradation, EnvironmentalHydrolysisProtein BindingBinding SitesUbiquitin-Protein LigasesUbiquitinationCatalysisMutationCell LineCysteine EndopeptidasesEscherichia coliModels, MolecularProtein Structure, TertiaryPhosphorylationRecombinant ProteinsBase SequenceHydrogen-Ion ConcentrationUbiquitinsCatalytic DomainSequence Homology, Amino AcidOxidation-ReductionCells, CulturedEndopeptidasesProtein Processing, Post-TranslationalBacterial ProteinsPeptide HydrolasesProtein ConformationModels, BiologicalMutagenesis, Site-DirectedElectrophoresis, Polyacrylamide GelCrystallography, X-RayMultienzyme ComplexesSignal TransductionSaccharomyces cerevisiaeEndoplasmic Reticulum-Associated DegradationChromatography, High Pressure LiquidStructure-Activity RelationshipEnzyme ActivationCloning, MolecularTime FactorsMolecular WeightTemperatureHeLa CellsProteinsRNA, MessengerCarrier ProteinsCattleProtein TransportPeptidesRecombinant Fusion ProteinsProtease InhibitorsAdenosine TriphosphateSaccharomyces cerevisiae ProteinsEndoplasmic ReticulumMolecular StructureAmino Acids