Extended Data Fig. 4: Comparison of PCS values determined during apo and turnover conditions and correlation of PCSs during turnover conditions with the open structure of Adk.

(a) Overlay of PCS values obtained for apo and Mg²⁺ADP conditions. Values were determined from [¹H-¹⁵N]-HSQC comparison in Zn²⁺ and Co²⁺ states. Note the sizable loss of PCS in the apo state compared to the closed state, indicating a more open structure in the absence of ligand. (b) Difference in PCS values for apo and turnover conditions. Large absolute differences of > 0.1 ppm are observed for many residues. (c) Zoom in of [¹H-¹⁵N]-HSQC spectra in either 20 mM Mg²⁺ADP or apo conditions of Co²⁺ Adk. Noticeable line broadening is observed for apo conditions. (d) Fit of open state (4AKE⁶⁸) to observed PCS shift data during catalytic turnover. (e) Best-fit tensor for PCS to open state structure. (f) Calculated PCSs for open state structure when fit with observed PCSs. A poor fit is found as the observed PCSs do not report on the open state structure. (g) The PCS difference expected between the open and closed state structures. Differences of |0.5 ppm| or greater would be expected for residues in AMP lid and core domain near the ATP lid.