SIRT7 is a member of a famiy of proteins called sirtuins (SIR2-like proteins) and are present in prokaryotes and eukaryotes. All SIR2-like proteins have a sirtuin core domain, which contains a series of sequence motifs conserved in organisms ranging from bacteria to humans. Bacterial, yeast, and mammalian sirtuins are able to metabolize NAD+ and several act as mono-ADP-ribosyltransferases. The enzymatic function of sirtuins is not yet completely understood but recent reports of histone-activated SIR2-mediated NAD+ metabolism and NAD+-activated SIR2-mediated histone deacetylation suggest a possible coupled reciprocal activation mechanism involving interactions of SIR2 with NAD+ and the N-ε-acetyl-lysine groups of acetylated histone.
