title: Structural basis for the NAD-dependent deacetylase mechanism of Sir2.
abstract: The NAD-dependent histone/protein deacetylase activity of Sir2 (silent information regulator 2) accounts for its diverse biological roles including gene silencing, DNA damage repair, cell cycle regulation, and life span extension. We provide crystallographic evidence that 2'-O-acetyl ADP-ribose is the reaction product that is formed at the active site of Sir2 from the 2.6-A co-crystal structure of 2'-O-acetyl-ADP-ribose and Sir2 from Archaeoglobus fulgidus. In addition, we show that His-116 and Phe-159 play critical roles in the catalysis and substrate recognition. The conserved Ser-24 and Asp-101 contribute to the stability for NAD binding rather than being directly involved in the catalysis. The crystal structures of wild type and mutant derivatives of Sir2, in conjunction with biochemical analyses of the mutants, provide novel insights into the reaction mechanism of Sir2-mediated deacetylation.
authors.affiliation: National Creative Research Initiative Center for Structural Biology and Department of Life Science, Pohang University of Science and Technology, Hyo-ja dong, San31, Pohang, KyungBook 790-784, South Korea.
authors.forename: Jeong-Ho
authors.initials: JH
authors.lastname: Chang
authors.forename: Hyun-Chul
authors.initials: HC
authors.lastname: Kim
authors.forename: Kwang-Yeon
authors.initials: KY
authors.lastname: Hwang
authors.forename: Joon-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Jackson
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Bell
authors.forename: Yunje
authors.initials: Y
authors.lastname: Cho
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D001105:Archaea / Q000201:enzymology*; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D006655:Histone Deacetylases / Q000737:chemistry* / Q000378:metabolism; D009243:NAD / Q000378:metabolism*; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000737:chemistry*; D056565:Sirtuin 2; D037761:Sirtuins / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D009243:NAD; D000246:Adenosine Diphosphate Ribose; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D006655:Histone Deacetylases