Figure 1.

Model of local action of histone acetyltransferases and histone deacetylases. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) are recruited to their target promoters through a physical interaction with a sequence-specific transcription factor (TF). They usually function within a multimolecular complex ('enzymatic complex'), in which the other subunits are necessary for them to modify nucleosomes around the binding site. These enzymes can also modify factors other than histones (protein X) to regulate transcription. Note that the position of the modified nucleosome that is shown has been chosen at random for this figure.