1M2H: Sir2 Homologue S24a Mutant-adp Ribose Complex

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.
PDB ID: 1M2HDownload
MMDB ID: 22606
PDB Deposition Date: 2002/6/24
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1M2H: monomeric; determined by author
Molecular Components in 1M2H
Label Count Molecule
Protein (1 molecule)
Silent Information Regulator 2(Gene symbol: AF_RS08430)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB