Fig. 3: XL44 interactions with hRpn13 Pru defined by integrated NMR and X-ray crystallography.
From: A structure-based designed small molecule depletes hRpn13Pru and a select group of KEN box proteins
a Selected regions focusing on the XL44 methyl group (top) or hRpn13 Leu33, Val38, and Lys42 (bottom) from a 1H, 13C half-filtered NOESY (100 ms) experiment acquired on a sample containing 0.4 mM 13C-labeled hRpn13 Pru and equimolar unlabeled XL44 dissolved in NMR buffer. b Chemical structure of XL44-13C6-CB (left panel) and selected region from a 1H, 1H plane of a 1H, 13C half-filtered NOESY (100 ms) experiment acquired without incrementing the 13C dimension on a sample with 0.4 mM hRpn13 Pru mixed with equimolar of XL44-13C6-BA in NMR buffer (right panel). c Overlay of X-ray structure (black) and after refinement by integrating the NMR data (purple) for the XL44-bound region. The methyl group of XL44 as well as side chains of Leu33, Val38, and Lys42 are reoriented in the integrated structure (shown as black arrows) by NOE data. d 2Fo − Fc electron density map contoured at 1.7σ displayed for one asymmetric unit of the ternary hRpn13 (purple), ubiquitin (yellow) and XL44 (pink) complex. Nitrogen (blue), oxygen (red), hydrogen (white), and fluorine (green) atoms of XL44 and bound water molecules (red spheres) are displayed.
