Structural insights into Cullin4-RING ubiquitin ligase remodelling by Vpr from simian immunodeficiency viruses
Fig 3
Cryo-EM analysis of CRL4-NEDD8DCAF1-CtD/Vprmus/SAMHD1 conformational states.
(A) Two views of an overlay of CRL4-NEDD8DCAF1-CtD/Vprmus/SAMHD1 cryo-EM reconstructions (conformational state-1 –light green, state-2 –salmon, state-3 –purple). The portions of the densities corresponding to DDB1 BPA/BPC, DCAF1-CtD and Vprmus have been superimposed. (B) Two views of a superposition of DDB1/DCAF1-CtD/Vprmus and CUL4/ROC1 (PDB 2hye) [15] molecular models, which have been fitted as rigid bodies to the corresponding cryo-EM densities; the models are oriented as in A. DDB1/DCAF1-CtD/Vprmus is shown as in Fig 2A, CUL4 is shown as cartoon, coloured as in A and ROC1 is shown as cyan cartoon. (C) Comparison of outermost CUL4 stalk orientations observed in the cryo-EM analysis presented here (states-1 and -3, coloured as in B, show 119.5° rotation of DDB1 BPB) to the two most extreme stalk positions present in previous crystal structures (PDB 4a0l [13], PDB 6dsz [123], coloured grey, show 143.4° DDB1 BPB rotation).