Figure 1.

A model for the generation of transcriptionally active and inactive chromatin domains by post-translational histone modification. (a) Histone acetyltransferases (HATs) generate patterns of acetylation (Ac) recognized by other transcriptional regulators, such as the bromodomain-containing (Bromo) factors TAFII250, PCAF and GCN5, leading to chromatin 'opening' and gene activation. (b) Conversely, the conserved histone methyltransferase (HMT) SUV39H1 methylates (Me) histone H3, which is then bound by the heterochromatin-associated chromodomain (Chromo) protein HP1/Swi6, establishing a silent chromatin domain.