Structural analysis of antigenic variation and adaptive evolution of the H5N1 neuraminidase gene
Fig 9
Conformational Free Energy Landscapes (FELs) of the NA1 WT and Variants.
The FELs were constructed by projecting the 300 ns molecular dynamics trajectories onto the first two principal components (PC1 and PC2), which capture the maximum variance in the overall backbone motion. (A) The Wild-Type (WT) shows a bi-modal landscape with two connected deep minima (dynamic switching). (B) The K207W mutant exhibits a single, deep, rigid minimum (structural lock). (C) The E229S mutant displays a fragmented, shallow landscape indicative of maximum conformational entropy (disordered collapse). (D-F) show the landscapes for K207H (dynamic preservation), K207I (expanded disorder), and G324T (single-axis restriction), respectively.