FIGURE 7.

Calixarenes block the histone-binding activity of the MLL5 PHD finger in vitro and in vivo. a, crystal structure of the MLL5 PHD finger in complex with H3K4me3 peptide (PDB code 2LV9). The aromatic cage residues are colored green. b, superimposed ¹H,¹⁵N HSQC spectra of MLL5 PHD, collected as first H3K4me3 peptide and then (1), (4), or (7) were titrated in. The spectra are color-coded according to the protein:peptide:calixarene molar ratio. c, quantitation of the interaction of MLL5 PHD with H3 (black) or H3K4me3 (blue) peptides by fluorescence polarization (left) or fluorescence polarization displacement (right) by (1). d, overlays of ¹H,¹⁵N HSQC spectra of the H3K4me2-bound MLL5 PHD recorded during titration with (1) or (7). e, binding of the GST-fusion MLL5 PHD finger to the indicated biotinylated histone peptides in the absence or presence of the indicated calixarenes.