Function
Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes (CRLs), which mediate the ubiquitination of target proteins. Recruits the E2 ubiquitin-conjugating enzyme CDC34/UBC3 to the complex and brings it into close proximity to the substrate. Also stimulates CDC34/UBC3 autoubiquitination and promotes the neddylation of CDC53 and RTT101. Component of the SCF(CDC4) ubiquitin ligase required for ubiquitination of the cyclin-dependent kinase inhibitor SIC1 and for the G1-to-S phase transition. Component of the RTT101(MMS1-MMS22) ubiquitin ligase that promotes fork progression through damaged DNA or natural pause sites. Component of the CRL3(ELA1) ubiquitin ligase required for ubiquitinaton of RPB1, the largest subunit of RNA polymerase II (Pol II), which targets Pol II for proteasomal degradation in DNA-damaged cells.