Supplemental Figure 1 WT ub ub K48R ub K63R 2 2 2 hrs 170 100 72 54 46 2 2 2 hrs 170 100 72 54 46 35 24 17 Supplemental Figure 1. In vitro ubiquitylation assay with ubiquitin variants. The ubiquitylation complex consisting of GST-RGLG2, MMZ2 and UBC35 can form ubiquitin chains with WT ubiquitin (left panel), with ubiquitin variant ub K48R, in which Lys 48 was replaced by Arg (middle panel), but not with ubiquitin variant K63R, in which Lys 63 was replaced by Arg (right panel), underlining the specificity for ub chains linked via Lys 63. Reaction conditions were similar to Figure 2, but a different anti-ubiquitin antibody (Bachmair et al., 1990) was used for detection. Supplemental Figure 1