FIGURE 4.

NMR mapping of the PfI3 sites interacting with PfPP1. A, overlaid {¹H-¹⁵N} HSQC of ¹⁵N-PfI3, free (gray spectrum), and in presence of an equimolar amount of PfPP1 (superimposed red spectrum). Interaction induces broadening of numerous resonances; see for example the isolated Gly⁷³ resonance, in the upper part of the spectrum. The amide side chain resonance of Trp⁴⁵ is shown as an inset. B, same color code is applied for the overlaid spectra corresponding to ¹⁵N-PfI3W45A free or in presence of PfPP1. Resonances of PfI3 are all annotated (A), although the annotated resonances of ¹⁵N-PfI3W45A are restricted to those showing perturbation upon PfPP1 addition or located around Ala⁴⁵ (B). The supplemental Fig. S2 provides a comparison of the (¹H-¹⁵N} HSQC of ¹⁵N-PfI3 and ¹⁵N-PfI3W45A. The graphics below the spectra show the normalized ratio of the intensity of a given resonance in the free PfI3 and in the 1:1 PfI3:PfPP1 spectra (C) or free PfI3W45A and in the 1:1 PfI3W45A:PfPP1 spectra (D), reported along the PfI3 sequence.