Method for identifying a compound that modulates SIR2 protein activity
The present invention relates to a method for identifying compounds that modulate the activity of sirtuin deacetylase protein family members. Compounds of the invention are identified by designing or screening for a compound which binds to at least one amino acid residue of the newly identified nicotinamide inhibition and base exchange site of Sir2 and testing the compound for its ability to modulate the activity of the Sir2 protein. Compositions and methods for preventing or treating diseases or disorders associated with Sir2 are also provided.
1. A method for identifying a compound that binds to or inhibits the histone deacetylase activity of a silent information regulator 2(Sir2) protein comprising:
a) generating on a computer a three-dimensional structure of a nicotinamide inhibition and base exchange site of a Sir2 protein of SEQ ID NO:1 in complex with nicotinamide, wherein the nicotinamide inhibition and base exchange site consists of amino acid residues 44, 64, 67, 116, 117 and 184 of SEQ ID NO:1, wherein the structural coordinates of amino acid residues 44, 64, 67, 116, 117 and 184 of SEQ ID NO:1 and nicotinamide are obtained by X-ray diffraction of a crystal of a complex of a Sir2 protein consisting of the amino acid sequence of SEQ ID NO:1 and an N-terminal hexahistidine tag, adenosine diphosphate hydroxymethyl pyrrolidinediol, an acetyl-lysine 16 histone H4 peptide, and nicotinamide, wherein the crystal has space group P3 2 21 and unit cell parameters of a=b=105.94 Å, and c=67.1 Å, and diffracts X-rays to a resolution of 2.05 Å;
b) employing the three-dimensional structure of the nicotinamide inhibition and base exchange site to design or screen for a compound that potentially binds to said nicotinamide inhibition and base exchange site; and
c) testing the compound designed or screened for in (b) by contacting the compound with the Sir2 protein of SEQ ID NO:1 and identifying compounds that bind to or inhibit the histone deacetylase activity of the Sir2 protein of SEQ ID NO:1.