SIR2_Af2: Archaeal and prokaryotic group which includes Archaeoglobus fulgidus Sir2-Af2, Sulfolobus solfataricus ssSir2, and several bacterial homologs; and are members of the SIR2 family of proteins, silent information regulator 2 (Sir2) enzymes which catalyze NAD+-dependent protein/histone deacetylation. Sir2 proteins have been shown to regulate gene silencing, DNA repair, metabolic enzymes, and life span. The Sir2 homolog from the archaea Sulfolobus solftaricus deacetylates the non-specific DNA protein Alba to mediate transcription repression.
Comment:The acetylated Lys side chain has an extended conformation. H118, V163, F165, L169, and V196 side chains form van der Waals interactions with the aliphatic atoms of the Lys side chain. The acetyl methyl group is in van der Waals contact with I102 and H118.