Download MendeleyStructure-based mechanism of ADP-ribosylation by sirtuins.
Hawse, W.F., Wolberger, C.(2009) J Biol Chem 284: 33654-33661
- PubMed: 19801667
- DOI: https://doi.org/10.1074/jbc.M109.024521
- Primary Citation of Related Structures:
3JR3 - PubMed Abstract:
Sirtuins comprise a family of enzymes found in all organisms, where they play a role in diverse processes including transcriptional silencing, aging, regulation of transcription, and metabolism. The predominant reaction catalyzed by these enzymes is NAD(+)-dependent lysine deacetylation, although some sirtuins exhibit a weaker ADP-ribosyltransferase activity. Although the Sir2 deacetylation mechanism is well established, much less is known about the Sir2 ADP-ribosylation reaction. We have studied the ADP-ribosylation activity of a bacterial sirtuin, Sir2Tm, and show that acetylated peptides containing arginine or lysine 2 residues C-terminal to the acetyl lysine, the +2 position, are preferentially ADP-ribosylated at the +2 residue. A structure of Sir2Tm bound to the acetylated +2 arginine peptide shows how this arginine could enter the active site and react with a deacetylation reaction intermediate to yield an ADP-ribosylated peptide. The new biochemical and structural studies presented here provide mechanistic insights into the Sir2 ADP-ribosylation reaction and will aid in identifying substrates of this reaction.
Organizational Affiliation:
Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
