Figure 1. Schematic representation of closed (A) and open (B) state Cul-RING Ligase (CRL)s.
A sketch to present the effect of Cul neddylation in CRLs. Cul have two domains: CulNTD (dark blue) and CulCTD (dark gray) where CulCTD consists of WHB domain, 4HB, and α/β-domains (shown with asterisks). Adaptor and SR proteins bind to CulNTD. Rbx1 (orange) binds to CulCTD. Ubiquitin-carrier E2 enzyme (green) binds to Rbx1 for substrate ubiquitination. Nedd8 (N8, shown in purple) conjugates to the CulCTD H29 of the WHB domain (K724 on Cul5, shown with a pink star) and leads to significant conformational change in CulCTD. Crystal structures report the distance between E2 Cys and the substrate in the closed state as ∼50–60 Å [26,57].