Interactions between histone-modifying enzymes and histone modifications associated with the silencing of gene expression. DNA methylation catalyzed by DNA methyl transferases and methyl-binding domain proteins can recruit histone deacetylases and histone methyl transferases that further repress gene transcription. DNMT, DNA methyltransferase; HDAC, histone deacetylase; HP, histone-binding protein; PRC, Polycomb repressive complexes; Suv, suppressor of variegation; SWI/SNF, switch/sucrose nonfermentable.