Fig. 3: Mapping the KAP1Hbox-HP1αCSD binding interface.
a Overlayed 1H,15N HSQC spectra of 15N-labeled HP1αCSD recorded in the presence of increasing amount of KAP1Hbox peptide. Spectra are color coded according to the protein:peptide molar ratio. b Bar plot of normalized CSPs in 1H,15N HSQC spectra of 15N-labeled HP1αCSD induced by the fourfold molar excess of KAP1Hbox peptide. Disappeared peaks are indicated by red bars and labeled. c Surface representation of the HP1αCSD-KAP1Hbox’ complex, colored as in Fig. 2c. KAP1Hbox’ is shown as green stick. The residues of HP1αCSD, resonances of which disappear in (b) are mapped onto the surface, colored orange and yellow and labeled. d Overlayed 1H,15N HSQC spectra of the 15N-labeled W174A mutant of HP1αCSD recorded in the presence of increasing amount of wild type KAP1Hbox peptide. e Overlayed 1H,15N HSQC spectra of 15N-labeled HP1αCSD recorded in the presence of the V488E mutant of KAP1Hbox peptide. Spectra are color coded according to the protein:peptide molar ratio. f Overlayed 1H,15N HSQC spectra of the 15N-labeled I165E mutant of HP1αCSD recorded in the presence of increasing amount of KAP1Hbox peptide and color coded according to the protein:peptide molar ratio. Western blot analysis of pull-down assays with Strep-tagged wild type and mutated HP1α (g) and Strep-tagged wild type and mutated KAP1 with FLAG-tagged HP1α constructs (h). controls: Strep-tagged GFP. The data are representative of 3 biological replicates with identical results. n = 3 Source data are provided as a Source Data file.
