ELP3: Elp3, a yeast A-type HAT, appears to have a direct role in transcription in that it is part of the RNA polymerase II holoenzyme and is involved in transcriptional elongation. In S. cerevisiae, the three-subunit elongator complex binds tightly to RNA polymerase II and its hyperphosphorylated C-terminal repeat domain (CTD), participating in an elongation-competent form of holoenzyme. Elp3, the smallest elongator subunit, was identified by peptide mass spectrometry and found to have GNAT homology. Because of its GNAT homology, recombinant Elp3 was produced from insect cells and tested for HAT activity in in-gel assays. Under these conditions, Elp3 was able to acetylate all four core histones when presented with them individually (1)

Reference
1. Sterner, D.E.&Berger, S.L.Acetylation of histones and transcription-related factors. Microbiol. Mol. Biol. Rev.2000;64(2):435-459. PMID: 10839822.