For example, histone deacetylase 1 (HDAC1) and HDAC2 can remove the activating mark histone 3 acetyl lysine 9 (H3K9Ac), then the histone methylase G9a can add methyl groups, while the histone demethylase lysine specific demethylase 1 (LSD1) can remove the activating mark H3K4me.
The NuRD complex contains seven subunits: the histone deacetylase core proteins HDAC1 and HDAC2, the histone-binding proteins RbAp46 and RbAp48, the metastasis-associated proteins MTA1 (or MTA2 / MTA3), the methyl-CpG-binding domain protein MBD3 (or MBD2) and the chromodomain-helicase-DNA-binding protein CHD3 (aka Mi-2alpha) or CHD4 (aka Mi-2beta).