Fig. 1. Intermolecular NOEs. 2D 15N-filtered/13C-separated NOE spectra (120 ms mixing time) recorded on (A) a 1:1 HPr(15N)–IIAGlc(13C) complex and (B) a 1:1 HPr(13C)–IIAGlc(15N) complex, specifically illustrating intermolecular NOE contacts from protons attached to 13C (F1 axis) to amide protons attached to 15N (F2 axis). Residues from HPr are denoted in italic. Intermolecular NOEs were assigned with the aid of complementary 2D 15N-separated/13C-filtered and 15N-filtered/13C-filtered NOE spectra. Note that the aromatic 13C resonances are folded.