Fig. 4: Comparison of HDX of the N-terminal hexahistidine tagged proteins (WT and W90F) in the presence liposomes with BMP.
a Difference plots illustrate difference in HDX over the measured time points between His6-Hsp70 WT incubated with liposomes without and with BMP (top panel); and His6-Hsp70 W90F incubated with liposomes without and with BMP (bottom panel). Cyan line indicates: 15 s, orange line: 1 min, grey line: 10 min, yellow line: 100 min, blue line: 1000 min. Residues comprising a region with a significant difference in HDX are indicated. The peptides are arranged according to their position from N- to C-terminus (Supplementary Data 5, Tables 4 and 5). Dotted grey lines indicate the 98% CI as a threshold for significance. To note, the effect on peptide 43–68 is significant when His6-WT is incubated with liposomes with BMP and absent when incubated with liposomes without BMP (Fig. S16), therefore it is attributed to the interaction with BMP lipid. b Regions showing significant variation of HDX in His6-Hsp70 WT upon BMP binding are deciphered by comparison with the His6-Hsp70 W90F analysis and are coloured in the crystal structure of the NBD. Red colour indicates constitutive BMP-specific effect; blue indicates destabilization upon BMP binding; orange indicates unspecific binding to lipids artificially induced by the N-terminal tag; green indicates binding to BMP artificially induced by the tag.
