P300-CBP coactivator family

E1A binding protein p300
Crystallographic structure of the histone acetyltransferase domain of EP300 (rainbow colored, N-terminus = blue, C-terminus = red) complexed with the inhibitor lysine-CoA (space-filling model, carbon = white, oxygen = red, nitrogen = blue, phosphorus = orange).
Identifiers
Symbol	EP300
Alt. symbols	p300
Entrez	2033
HUGO	3373
OMIM	602700
PDB	3biy
RefSeq	NM_001429
UniProt	Q09472
Other data
EC number	2.3.1.48
Locus	Chr. 22 q13.2

The p300-CBP coactivator family is composed of two closely related transcriptional co-activating proteins (or coactivators):

Both p300 and CBP interact with numerous transcription factors and act to increase the expression of their target genes.

p300 and CBP have similar structures. Both contain five protein interaction domains: the nuclear receptor interaction domain (RID), the CREB and MYB interaction domain (KIX), the cysteine/histidine regions (TAZ1/CH1 and TAZ2/CH3) and the interferon response binding domain (IBiD). The last four domains, KIX, TAZ1, TAZ2 and IBiD of p300, each bind tightly to a sequence spanning both transactivation domains 9aaTADs of transcription factor p53. In addition p300 and CBP each contain a protein or histone acetyltransferase (PAT/HAT) domain and a bromodomain that binds acetylated lysines and a PHD finger motif with unknown function. The conserved domains are connected by long stretches of unstructured linkers.

p300 and CBP are thought to increase gene expression in three ways:

p300 regulates transcription by directly binding to transcription factors (see external reference for explanatory image). This interaction is managed by one or more of the p300 domains: the nuclear receptor interaction domain (RID), the CREB and MYB interaction domain (KIX), the cysteine/histidine regions (TAZ1/CH1 and TAZ2/CH3) and the interferon response binding domain (IBiD). The last four domains, KIX, TAZ1, TAZ2 and IBiD of p300, each bind tightly to a sequence spanning both transactivation domains 9aaTADs of transcription factor p53.