ThesisAuthors: Celic, Ivana (2006)
The Sir2 proteins, also known as sirtuins, represent a large and highly conserved family of NAD+-dependent protein deacetylases that control various fundamental biological proceses.
The baker’s yeast, Saccharomyces cerevisiae, has five members of this family, Sir2p and Hst1-4p, important for regulation of transcriptional silencing and genomic stability. Hst3p and Hst4p are two redundant sirtuins with the major role in maintenance of genomic stablity. They control genomic stability by regulating the level of acetylation of histone H3 lysine 56. This residue, present in the core of the nucleosome surface, is acetylated during the S phase of the cel cycle and contributes to the repair proceses active during DNA replication. At the end of the S phase, K56 of histone H3 is deacetylated ... 
