A collapsed ML tree of EP300 and conserved domains within consensus sequences. The original tree can be seen in Additional file 4. From left to right, the displayed conserved domains were zf-TAZ (pfam02135), KIX (pfam02172), Bromo_cbp_like (cd05495), RING_CBP-p300 (cd15802), PHD_p300 (cd15646), HAT_KAT11 (pfam08214), ZZ_CBP (cd02337), ZnF_TAZ (smart00551) and Creb_binding (pfam09030). The Creb_binding domain annotated by CDD search was called nuclear receptor coactivator binding domain (NCBD) or interferon binding domain (IBiD) elsewhere [6, 8]. CH1-3 indicate three cysteine-histidine-rich domains

Positively selected branches reported by branch-site test. Fishes (a), mammals (b) and sauropsids (c) are displayed separately. A red square indicates that the multiple testing corrected p value was lower than 0.05; a red circle indicates that the multiple testing corrected p value was higher than 0.05, but the uncorrected p value was lower than 0.05

Structures of the zf-TAZ domain and its flanking regions. The source sequences were Ep300a of D. rerio (a), Ep300b of D. rerio (b), Ep300a of O. latipes (c) and Ep300b of O. latipes (d). The first (always MET-1) and last residue of each sequence used for modeling are labeled; α-helixes are colored red

Tissue expression profiles of ep300 genes of different species. Four types of Pearson correlation coefficient (r) values were calculated: an r value following “ep300a” indicates the correlation between ep300a of a teleost and ep300 of L. oculatus; an r value following “ep300b” indicates the correlation between ep300b of a teleost and ep300 of L. oculatus; an r value following “average” indicates the correlation between average values of ep300a and ep300b of a teleost and ep300 of L. oculatus; r_1,2 indicates the correlation between ep300a and ep300b of a teleost. A single asterisk (*) indicates that the correlation was significant (p < 0.05); two asterisks (**) indicate that the correlation was very significant (p < 0.01)