Fig. 3.

The mutations of Rqt3 in the residues crucial for the ubiquitin-binding domain diminished RQC. a Alignment of the conserved residues in the CUE domains of Rqt3, Vps9, and Cue2. The mutated residues in Rqt3-Ub-m were shown in red. b CUE domain of Rqt3 interacted directly with ubiquitin, and it was abolished by Ub-m mutations. c The mutations of Rqt3 in the residues crucial for the ubiquitin-binding domain diminished RQC. d The mutation in the ubiquitin binding of Rqt3 is dispensable for the association of Rqt2-4 in Rqt1-ribosome complex. e The distribution of Rqt2-4 proteins in polysome profiles of Rqt3-Ub-m mutant. f The expression levels of endogenously HA-tagged Rqt2 and Rqt4, Flag-tagged Rqt3 and Rqt3-Ub-m proteins in Rqt3-Ub-m mutant cells