Fig. 5. Purification and analysis of the deacetylase activity of Sir2p-containing complexes purified from mutant cells. Aliquots of the indicated fractions across the gel-filtration column were assayed for NAD-dependent deacetylase activity. (A) The amount of deacetylation mediated by Sir2p containing complexes purified from cells with a mutant Sir2p (H364Y) are shown in graphical form. The immunoblot profile under the graphs is for Sir2p. (B) The amount of deacetylation mediated by Sir2p-containing complexes purified from cells lacking Rpd3p is shown. The immunoblot profile under the graphs is for Sir2p.