Probing phosphoprotein P binding to M2-1_58–177 by NMR perturbation experiments.

Abstract

<p>(A, B, C and D) <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002734#s2" target="_blank">Results</a> of transferred cross-saturation (TCS) experiments carried out with 150 µM ²H¹⁵N-M2-1_58–177 in the presence of P (15 µM, 91% D₂O, 14.1 T, 293 K). (A) Close-up of the ¹H-¹⁵N HSQC spectra with methyl proton saturation of P (blue) and without (orange). (B) Per residue plot of reduced ¹H-¹⁵N HSQC cross-peak intensities, calculated as a ratio between intensities with (I_sat) and without (I₀) methyl proton saturation and corrected by the reduced cross-peak intensities measured in the absence of P. (C) and (D) Mapping of the TCS effect on the structure. ¹⁵N atoms of residues with Δ(I_sat/I₀)>mean+1sd are shown as purple spheres. The surface formed by these residues is colored in purple. (E, F, G and H) ¹H-¹⁵N HSQC cross-peak intensity perturbation experiments of ¹⁵N¹³C-M2-1_58–177 (50 µM) in the presence of P_100–166 (100 µM, 14.1 T, 298 K). (E) Close-up of the ¹H-¹⁵N HSQC spectra with P_100–166 (blue) and without (red). (F) Per residue plot of the resulting cross-peak intensity reduction relative to the reference intensity. (G) and (H) Mapping of the intensity variations on the structure. ¹⁵N atoms are shown as spheres for residues with ΔI/I₀>75% (blue) and >70% (cyan). The same color code is used for the surface representation.</p