Figure 5

Homology modeling of wild-type and mutant E2F1 around the R166 residue. Homology modeling of the E2F1 DNA binding domain using SWISS-MODEL [18]. Top: ANOLEA (Atomic Non-Local Environment Assessment) [19] and GROMOS (Groningen Molecular Simulation) [20] were used by SWISS-MODEL to assess the quality of the model structure of the E2F1 wild-type and E2F1 R166H mutant DNA binding domain. The y-axis represents the energy for each amino acid of the protein, with negative energy values (in green) representing a favorable energy environment and positive energy values (in red) representing unfavorable energy environments. Bottom: the predicted three-dimensional structure of residues VQK(R/H)R with the wild-type arginine-arginine residues shown in purple (bottom left), the mutated histidine residue shown in red and its arginine neighbor shown in blue (bottom right). The side chain of the histidine mutation is clearly predicted to be oriented approximately 90 degrees counterclockwise compared to the side chains of its wild-type arginine counterpart.