FIG. 9.

Model for interaction between Ufo1 and Ddi1. Ufo1 and Ufo1ΔUIM are shown in a complex with Skp1 (S) and Cdc53 (53) via contacts of both their F-box (F) and WD40 domains. (R is Rbx1). Interaction between the Ufo1 UIMs and the UbL domain of Ddi1 promotes degradation of Ufo1 and recycling of SCF^Ufo1 complexes. The interaction between Ddi1 and Ufo1 also involves its UbA domain that may need to be released from interaction with the UbL domain to make contact with the ubiquitin chains on Ufo1.