The C-terminal domains of ADA2 proteins determine selective incorporation into GCN5-containing complexes that target histone H3 or H4 for acetylation

► The C-terminal region targets ADA2 adaptor into histone specific SAGA or ATAC complex. ► ADA2a/b hybrid containing ATAC and SAGA complexes display partial in vivo function. ► Transcriptome analysis of ATAC mutants indicates deregulated histone acetylation.