Fig. 5: Substrate binding is confined to a small area of the translocation pathway.

a, b Thermostability shift values (ΔTm) determined at 0.1, 0.5, 1, 5, 10 mM substrate concentration for the wild type and single alanine replacement variants. Circles and error bars represent the mean and standard deviation of eight independent experiments for the wild type and 3–5 for the variants. Empty and filled circles represent ADP and ATP, respectively. Data for the wild-type protein are shown in black, whereas the variant data are shown in green. Note that in several occasions the mean value and error bars of ADP vs ATP groups are identical and consequently their graphical representation is superimposed, with ADP marker on top. Error bars are smaller than the symbol whenever not shown. The statistical evaluation was carried out as described in “Methods”. Significant values (p ≤ 0.01) are indicated by * or # for ADP and ATP, respectively. c TtAac matrix-open BKA-bound structure (PDB code: 6gci chain A) (left) and close-up view (right) showing the analysed residues in green stick and sphere for Gly representations. Helices are shown in wheat cartoon representation and are labelled. Source data for this figure are provided as a Source Data file.