FIGURE 9.

The Cdc34 acidic tail shows a preference for disulfide cross-linking to Cys-679 in the Cul1 basic canyon. A, Cul1 Western blot of reactions between either Cdc34 1C or Cdc34 2C proteins that had been activated with DPS and WT Cul1-Rbx1. B, same as in A, except K679C Cul1-Rbx1 was used. C, graph showing the fraction of either WT or K679C Cul1 subunits that cross-linked to either Cdc34 1C or Cdc34 2C proteins. Error bars, S.E. of measurement from duplicate data points. D, heat map showing the fraction of Cul1 converted to Cdc34-Cul1 cross-links for WT and all five cysteine mutant Cul1-Rbx1 proteins. Cdc34 proteins had been activated with DPS prior to their incubation with the Cul1-Rbx1 proteins. Values represent the average from duplicate measurements.