Phylogenetic tree and domain composition of HAG proteins. Maximum likelihood phylogenetic tree of HAG predicted proteins from Arabidopsis thaliana (At), Oryza sativa (Os), Solanum lycopersicon (Sl) and Zea mays (Zm). Bootstrap values higher than 50% are shown. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. AT1 (PF00583) and C-terminal BrD (PF00439) are conserved domains of GCN5-like members; N-terminal ELP (IPR006638) and C-terminal AT1 are domains of ELP3-like; N-terminal Hat1_N (PF10394) and C-terminal AT1 are motifs of HAT1-like members while the only AT1 domain is of HPA2-like proteins. Overlapping domains are hyphenated and represented with a continuous dotted line.