1. DCAFs, the Missing Link of the CUL4-DDB1 Ubiquitin Ligase
Jennifer Lee, Pengbo Zhou 
Molecular Cell 
Volume 26, Issue 6, Pages (June 2007)
DOI: /j.molcel
Copyright © 2007 Elsevier Inc. Terms and Conditions

2. Figure 1
A Model for the Assembly of the CUL4A-DDB1-DDB2 Ubiquitin Ligase Complex
CUL4A serves as a rigid scaffold, with its N-terminal domain forming direct contacts with the top surface (T) of DDB1-BPB, and its C-terminal domain recruiting Rbx1 (R) and the E2 ubiquitin-conjugating enzyme. The DDB1-BPA and DDB1-BPC double propeller folds into a clam-shaped structure that binds DCAFs and regulators of the CUL4 CRL. Within the triple DDB1 β propellers, the linker (represented by the short black ribbon) connecting DDB1-BPB and DDB1-BPA/DDB1-BPC exhibits enormous flexibility. DDB2 is a WD40 protein with one WDXR motif (depicted by the yellow dot) for DDB1 binding, as well as an additional binding determinant (α-helical domain) at the N terminus that forms contacts with the three conserved clusters of residues on the DDB1-BPC propeller (blue dots). It is noteworthy that the α-helical domain is not found in all DCAFs, and the schematic representation shown depicts the CUL4A-DDB1-DDB2 complex only, not a generalized model of the CUL4A-DDB1-DCAF complex. The top (T) and bottom (B) surfaces of each β propeller are indicated. S, substrate.
Molecular Cell  , DOI: ( /j.molcel )
Copyright © 2007 Elsevier Inc. Terms and Conditions