Role of Hsp70 ATPase Domain Intrinsic Dynamics and Sequence Evolution in Enabling its Functional Interactions with NEFs
(a) Distribution of residue mobilities Mi(1) in the global mode of motion calculated for the unbound Hsp70 ATPase domain. The horizontal bars on the upper abscissa indicate the ranges of the four subdomains IA, IB, IIA and IIB, colored as in Figure 1a. Subdomain IIB is distinguished by its enhanced mobility, with peaks at two regions: the C-terminal part of helix 8, and the β-hairpin loop. NEF-binding residues are indicated by the blue open circles (based on atom-atom distances) and red filled circles (based on ΔSASA). The diagram in the inset is color-coded to illustrate the global mobility profile (red: most mobile, blue: most rigid). (b) Weighted-average mobility profiles based on top-ranking ten GNM modes of motion, calculated using Equation 1 for the unbound ATPase domain (blue) and for the NEF-bound structures (red), averaged over three mammalian complexes (Table S1). Nucleotide-binding residues (G12-Y15, G201-G203, G230, E231, E268, K271, R272, S275, G338- S340, R342, I343, D366) are indicated by filled squares. (c) Change in mobility between bound and unbound ATPase domain, obtained by taking the difference of two curves shown in panel b. The dashed line corresponds to the zero level. NEF-binding residues are marked by filled squares.