| Modification Notes |
In Saccharomyces cerevisiae, the hyperphosphorylated form of RNA polymerase II (RNAP II) mediates transcription elongation, and associates with the elongator complex, which contains six subunits (1-3). The elongator complex can be separated into two subcomplexes; one consisting of Elp1, Elp2, and Elp3, and the other consisting of Elp4, Elp5, and Elp6 (1,2). Mutations in any of the elongator subunits confer similar phenotypes, which suggests that the Elp proteins function together (1,2). The elongator complex acetylates both core histones and nucleosomal substrates, and directs its activity specifically towards the amino-terminal tails of histone H3 and H4 (3). The elongator complex predominantly acetylates lysine-14 of histone H3 and lysine-8 of histone H4 (3,4). Elp3, the histone acetyltransferase subunit of the elongator complex, is required for sufficient acetylation of histone H3 and H4 (3-5). Cells deficient for Elp3 display slow growth adaptation, slow gene activation, and temperature sensitivity (5,6). |