Figure 4
From: Mapping the electrostatic potential of the nucleosome acidic patch
taken from the nucleosome structure (PDB-id: 2PYO).
Apparent pKa of H2A-H2B dimer core region measured by NH chemical shift perturbations. (a–e) Overlay of HSQC spectra at indicated pH values shown on the left, CSP-derived titration curves with fitted pKaapp in the middle, and the local structure on the right for selected residues. Best-fit values of pKa and standard deviation are shown on the titration curve, together with 95% confidence interval in brackets. As the resonance of L92 (panel e) could not be tracked below pH 5.6, the fit is based on the pH 5.6–9.0 data. (f) Color coding of fitted pKaapp values on the H2A-H2B structure. (g) Color coding of the CSP between pH 6 to 8 on the H2A-H2B structure. Color coding in (f, g) indicated in the figure. Residues with no data are colored grey. Acidic patch residues and H2B H46 and H106 are shown as sticks. Structure is
