76E1E2E37polyubiquitinchain4863DUBUBDE150E2600E390DUB20UBDE3HECTE3RINGRINGU-boxPHDE3E3E3westernblotandstripWBstripwesternblotandimmunoprecipitationsSDSwesternblotinvitroubiquitinationassay29324hbufferAUBE1UbeH13-Uev1aheterodimercomplexHA-ubiquitinBAIPWBE3invitroubiquitin-bindingassay293K63-orK48-linkedubiquitinchainpetidesSDSWBstrip/StrippingtheblotUbK63MergeK6363Westernblotandimmunoprecipitations/SDSStrippingtheblotinvitroubiquitinationassay293UBE1UbeH13-Uev1aheterodimercomplexHA-ubiquitinIPWB