Figure 7.

R74-E40 salt-bridge may hinder NEDD8/WHB^SD association by disallowing compact conformations of the NEDD8 C-terminal tail. (A) Mean± one standard error of R74/E760 hydrogen bond occupancy for NEDD8-wt and dNEDD8 conjugates. (B) Snapshot from trajectory 1 of Cul1-WHB^SD~NEDD8 showing an intramolecular salt-bridge involving R74/E40. The Cα atom positions of A72/G76 are shown as pink spheres. (C) Combined probability distribution of the C-terminal tail conformation obtained from five 300 ns trajectories for each conjugate. The A72-G76 distance varies from 0.74 to 0.9 nm in crystal complexes of Cul1/5-WHB^SD~NEDD8. (D) Mean ± one standard error of the C-terminal tail conformation across all five trajectories for each conjugate.