Figure 3

Ribbon and balls and sticks rendering of a representative snapshot from molecular simulations carried out for model VHL-Elongin C-HIF-1 alpha complexes. The ribbon model of VHL and Elongin C protein fragments are colored orange and purple, respectively, while the fragment of HIF-1α protein is shown in green. The first and last snapshots from the simulation trajectory of the complex including wild type VHL protein indicates a remarkably stable protein complex (A,B). The Asn78Tyr mutation (C) remarkably deforms the 77-83 loop structure in the VHL protein. This deformation spreads over the Thr100-Arg107 loop of VHL (marked by red arrow) which finally results in a weakened interaction between this loop and the HIF-1alpha protein (shown by green arrow). The deformed loop structure in VHL deforms substantially the neighboring loop (Arg82-Phe93) structure in Elongin C (shown in blue ellipse in Figure 3B and Figure 3C). Atomtype coloring (C, N, O, H atoms are colored grey, blue, red and white, respectively) was used for the balls and sticks model which were applied for residues which are supposed to play key role in interchain interactions.