Structure of the p300 catalytic core and implications for chromatin targeting and HAT regulation

The crystal structure of the full catalytic core of p300 reveals the unexpected presence of a RING domain, within the CH2 region, that folds over the HAT-domain substrate-binding pocket. Mutations that destabilize the RING-HAT interaction and increase acetyltransferase activity in vitro are also found in B-cell lymphomas, thus suggesting an important function for this autoinhibitory interaction in vivo.