FIGURE 7.

Multiple histone H2A and H3 residues located near histone H4 Lys⁴⁴ are needed for proper H3 Lys³⁶ di- and trimethylation. A, a zoomed in view of the nucleosome is shown indicating multiple residues in the close proximity within 5 angstroms of histone H4 Lys⁴⁴ residue. Representative residues that are needed for H3 Lys³⁶ di- and trimethylation are labeled. H4 Lys⁴⁴ is marked in red; H2A Ile¹¹², Leu¹¹⁶, and Leu¹¹⁷ are marked in blue; and H3 Arg⁵², Ile¹¹², Asn¹⁰⁸, and Val¹¹⁷ are marked in yellow. B and C, whole cell extracts prepared from cells expressing WT histones or the indicated histone mutants are immunoblotted with H3 Lys³⁶ methyl-specific antibodies. The asterisks denote nonspecific bands. Immunoblot for histone H3 serve as loading controls. D, the histone residues with H3 Lys³⁶ di- and trimethyl defects have been shown to form a patch on the surface of the nucleosome. H4 Lys⁴⁴ is marked in red; and H2A Ile¹¹², Leu¹¹⁶, and Leu¹¹⁷ are marked in blue; and H3 Arg⁵², Ile¹¹², and Val¹¹⁷ are marked in green. H3 Asn¹⁰⁸ is not exposed at the surface of the nucleosome. These two structural figures were generated by Pymol.