Hat2 Background Information Hat1, Hat2 and Hif1 proteins are subunits of the type B histone acetyltransferase (HAT-B) from Saccharomyces cerevisiae that elicits histone acetylation activity. Chromatin remodeling is a critical component of transcription regulation that utilizes acetylation of nucleosomal histones. Acetylation results in an allosteric change in the nucleosomal conformation and an increased accessibility of DNA to transcription factors. Conversely, the deacetylation of histones is associated with transcriptional silencing (1). Gcn5 (also designated Ada4), Hat1 and Hat2 have been identified as yeast histone acetylases (2,3). Rps3 (also designated SD12), Hda1 and Sap30 have been identified as histone deacetylases (4-6). Sin3 (also designated Rpd1, Gam2, Ume4 or Sdi1) is involved in the transcriptional repression of many genes.
