Structural basis for nicotinamide cleavage and ADP-ribose transfer by NAD(+)-dependent Sir2 histone/protein deacetylases.

ABSTRACT: Sir2 enzymes are broadly conserved from bacteria to humans and have been implicated to play roles in gene silencing, DNA repair, genome stability, longevity, metabolism, and cell physiology. These enzymes bind NAD(+) and acetyllysine within protein targets and generate lysine, 2'-O-acetyl-ADP-ribose, and nicotinamide products. To provide structural insights into the chemistry catalyzed by Sir2 proteins we report the high-resolution ternary structure of yeast Hst2 (homologue of Sir two 2) with an acetyllysine histone H4 peptide and a nonhydrolyzable NAD(+) analogue, carba-NAD(+), as well as an analogous ternary complex with a reaction intermediate analog formed immediately after nicotinamide hydrolysis, ADP-ribose. The ternary complex with carba-NAD(+) reveals that the nicotinamide group ma

SUBMITTER: Zhao K 

PROVIDER: S-EPMC423234 | biostudies-literature | 2004 Jun

REPOSITORIES: biostudies-literature