Fig. 8. Fluorescence polarization assays for interaction of the Esa1 chromo domain with fluorescein-labeled unmodified H3 (circles), methyl-K4 H3 (triangles), methyl-K4/methyl-K9 H3 (open squares) and unmodified H4 (diamonds). Measurements were performed at 25°C in 50 mM sodium phosphate pH 8 and 25 mM NaCl buffer. Curves represent the best fit to the data as described in Materials and methods. Fraction bound corresponds to the normalized anisotropy.