The carboxyl terminus of fungal Rtt109s contain a Lys/Arg-rich sequence which is essential for H3K9ac in S. cerevisiae. (A) Using the ClustalW algorithm, S. cerevisiae Rtt109 was aligned with predicted Rtt109 sequences from fungi of the Ascomycota, Basidiomycota, Zygomycota (Rhizopus oryzae), Chytridiomycota (Batrachochytrium dendrobatidis and Allomyces macrogynus), and Microsporidia (Encephalitozoon cuniculi and Nosema ceranae). Identical amino acid residues are shaded in black, whereas similar amino acid residues are shaded in gray using Boxshade, version 3.2. (B) The 12MYC-RTT109 and 12MYC-RTT109(1–424) mutants expressed under the control of the ADH1 promoter on a CEN plasmid (pRB415A-12Myc) rescue the slow-growth phenotype of rtt109Δ gcn5Δ cells. †, vectors containing indicated genes were transformed into rtt109Δ gcn5Δ strains. (C) The basic carboxyl terminus of Rtt109 is absolutely required for H3K9ac but not for full H3K56ac. WCE from the indicated strains were resolved by 15% SDS-PAGE, transferred onto nitrocellulose paper, and immunoblotted with the antibodies indicated on the right of each blot.