HATs acetylate histones

Histone acetyltransferases (HATs) involved in histone modifications are referred to as A-type or nuclear HATs. They can be grouped into at least four families based on sequence conservation within the HAT domain: Gcn5/PCAF, MYST, p300/CBP and Rtt109. The p300/CBP and Rtt109 families are specific to metazoans and fungi respectively. Gcn5/PCAF and MYST family members have no significant sequence homology but share a globular alpha/beta fold with a common structure involved in acetyl-Coenzyme A (ACA) binding. Both use a conserved glutamate residue for the acetyl transfer reaction but may not share a common catalytic mechanism. The p300/CBP HAT domain has no homology with the other families but some structural conservation within theACA-binding core. In addition to histone acetylation, members of all 3 human HAT families have been shown to acetylate non-histones.

Summary from Reactome (R-HSA-3214847), read 2026-09-23.