FIGURE 5.
Mutation of the binding cage affects H3K4me3 binding. A, binding affinities of different ZCWPW2 CW mutants to H3K4me3 peptide determined by FP or ITC. F78del, deletion of Phe-78. B and D–G, ITC curves of selected mutants to H3K4me3 peptide. C, binding affinity of selected mutants to H3K4 peptides tested by FP, showing modest methylation selectivity after Phe-78 deletion or mutation. FP Kd values were calculated from duplicate measurements and fitted to a ligand binding curve using GraphPad Prism version 5 software. ITC Kd values were calculated from a single measurement, and errors were estimated by fit to a curve.