Fig. 4: Native state dynamics of exon 19 variants differ for profile 1 and profile 2.

a Backbone amide hydrogen exchange from HDX-MS experiments for all analyzable peptides at the 1 min labeling timepoint for wild type (grey circles), ΔL747-A750InsP (blue circles), L747P (blue diamonds), ΔE746-A750 (red circles), and ΔL747-P753InsS (red triangles) variants without ATP or inhibitor. Mean percent exchange (± SD) for three independent experiments across each of three separate protein preparations (two for ΔL747-A750InsP) is plotted against the median residue number of the peptide in wild type EGFR numbering. Secondary structure element positions are denoted at the top of the figure, with functionally important regions (β5/αD hinge, HRD motif, and activation loop) indicated. Wild type data are represented by two dashed grey lines corresponding to the range (± SD) for each point. The ΔE746-A750 and ΔL747-P753InsS variants both showed EX1 kinetics⁴⁸ in the HRD and DFG motif regions, so these data are shown separately (see Fig. 6). Positions of peptides i through vi (see c) are denoted at the bottom of the graph. b 1 min percent exchange data for the indicated EGFR variants mapped onto a crystal structure of wild type EGFR kinase domain in its active conformation (PDB ID: 7KXZ), with ATP (sticks) placed based on its position in PDB ID: 3VJO⁴⁵. The percent exchange of each amino acid was assigned using the DynamX software package (Waters) as described in Methods, and is color coded as shown on a scale from orange (100% exchange) to dark grey (no exchange). White regions in the binding pocket and elsewhere represent regions with EX1 exchange kinetics or with no coverage. Corresponding representations of 10 s and 10 min data are provided in Supplementary Fig. 7. c Mean percent exchange data (± SD) for key individual peptides i through vi, as marked in (a), for wild type (grey), ΔL747-A750InsP (blue), and ΔE746-A750 (red) as a function of the logarithm of deuterium labeling time are shown. See Supplementary Fig. 8 for additional peptides. Three independent HDX-MS experiments were performed on each of three separate protein preparations (two for ΔL747-A750InsP), with experimental parameters listed in Supplementary Table 1. Source data are provided as a Source data file.