Fig. 3: Effect of point mutations on the ATPase activity and molecular dynamics of TRAP1.

a, d, g, j ATPase activity of recombinant WT or mutant forms of human TRAP1 was measured as released PO₄^3-. Data are shown as fold change (with respect to the WT protein) and represent the mean ± SEM of n = 4 independent experiments done in triplicate with a Student’s t test analysis (***p < 0.001; n.s, non-significant). b, e, h, k Change in DF score to mutated positions in protomer A or B for each residue from WT to Mut Trap1 (b D260N; e P381S; h V556M; k A571T), projected onto the protein 3D structure (P_mutA, P_mutB). Protein views are rotated to allow a visualization of the mutation position, the identity of the protomer is labeled. Color code for DF scores: blue areas (positive values) correspond to lower mechanical coordination in Trap1 mutants with respect to the WT protein, whereas orange ones (negative values) indicate a higher coordination in the first. Gray/white areas are those unaffected by the mutation. c, f, i, l Variation in the mechanical connectivity index for each mutant along the sequence (Δη_mut). On the x axis numbering of zTrap1 as in PDB code 4IPE is shown together with the corresponding domains of protomer A and protomer B and the residue numbering is from 85 to 719. NTD: N-terminal Domain, residues 85–310; MD: Middle Domain divided in the subdomains Large Middle Domain (LMD), residues 311–470 and Small Middle Domain (SMD) residues 471–586; CTD: C-Terminal Domain, residues 587–719.