Genome-wide location of histone acetyltransferase Sas3 from Saccharomyces cerevisiae

We have investigated the genome-wide occupancy of Sas3p by ChIP-Chip, using tiled microarrays. Using this technique, it has been described that H3K14 and H3K9 acetylation is enriched at promoter regions and transcriptional start sites of active genes. Considering that Sas3p is a HAT whose main target in vitro is H3K14 we expected to detect Sas3 binding largely to promoter regions of genes. Surprisingly, we found that Sas3p is associated to the coding regions of genes, with a peak enrichment located) within the 5’ half of the ORF, and this enrichment drops substantially toward the 3’ region of the ORF. This result is very similar to that obtained for Yng1 genome-wide occupancy, also a component of the NuA3 complex, suggesting that this complex could be involved in transcriptional elongation, at least, in an initial step of the process. The experiments described in this study compare ChIP with an anti-HA antibody of a SAS3-HA tagged strain (BQS1217) to a control ChIP with an anti-HA antibody of a wild type strain (BY4742). Budding yeast samples were analyzed in exponential growing conditions (YPD). 2 biological replicates were performed.