Histone acetyltransferase (HAT) enzymes play important roles in the regulation
of chromatin assembly, RNA transcription, DNA repair and other DNA-templated
reactions through the lysine side-chain acetylation of histones and other
transcription factors. HATs fall into at least four different families based
on sequence conservation within the HAT domain. This includes Gcn5/PCAF, CBP/p300, Rtt109 and MYST
families. The different HAT families contain a structurally conserved central
region associated with acetyl-Coenzyme A (Ac-CoA) cofactor binding but
distinct catalytic mechanisms and structurally divergent flanking regions that
mediate different chromatin regulatory functions. Protein acetylation extends
beyond histones to other nuclear proteins and even cytoplasmic proteins to
regulate diverse biological processes including the regulation of cell cycle,
vesicular trafficking, cytoskeleton reorganization and metabolism.
CREB-binding protein (CBP)/p300 proteins are involved in various physiological
events including proliferation, differentiation and apoptosis. CBP/p300
proteins contain several well-defined protein-interaction domains as well as a
centrally located 380-residue HAT domain
[3][4][1][2].
The overall fold of the CBP/p300-type HAT domain consists of a central beta-
sheet comprising seven beta-strands surrounded by nine alpha-helices and
several loops
[3][4].
Some proteins known to contain a cBP/p300-type HAT domain are listed below:
- Animal CBP (also known as KAT3A), a coactivator for the cAMP-responsive
transcription factor CREB.
- Animal p300 (also known as KAT3B), binds to the adenoviral oncoprotein E1A.
- Arabidopsis thaliana HACs, involved in the ethylene signaling pathway
(HAC1, HAC2, HAC4, HAC5 and HAC12). All the HAC members share the CBP/p300-
type HAT domain; however, the HAT domain of HAC1 but not that of HAC2
possesses acetyltransferase activity, while the situation had not been
tested in the other HAC members
[2].
The profile we developed covers the entire CBP/p300-type HAT domain.