3jr3
Sir2 bound to acetylated peptideSir2 bound to acetylated peptide
Structural highlights
FunctionNPD_THEMA NAD-dependent protein deacetylase which modulates the activities of several enzymes which are inactive in their acetylated form. Has also depropionylation activity in vitro. Also able to ADP-ribosylate peptide substrates with Arg or Lys in the +2 position. The role of this function in vivo is not clear.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSirtuins 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. Structure-based mechanism of ADP-ribosylation by sirtuins.,Hawse WF, Wolberger C J Biol Chem. 2009 Nov 27;284(48):33654-61. Epub 2009 Sep 30. PMID:19801667[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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