Methionyl tRNA Synthetase Polynucleotides

Abstract

The invention provides metS polypeptides and DNA (RNA) encoding metS polypeptides and methods for producing such polypeptides by recombinant techniques. Also provided are methods for utilizing metS polypeptides to screen for antibacterial compounds.

1 - 13 . (canceled) 
   
   
       14 . An antagonist which inhibits the activity or expression of the polypeptide represented by SEQ ID NO: 2 or 4 wherein the polypeptide exhibits methionyl tRNA synthetase activity. 
   
   
       15 .- 17 . (canceled) 
   
   
       18 . A method for identifying compounds which interact with and inhibit an activity of the polypeptide represented by SEQ ID NO: 2 or 4, the method comprising:
 contacting a composition comprising the polypeptide with the compound under conditions to permit interaction between the compound and the polypeptide to assess the interaction of the compound, such interaction being associated with a component capable of providing a detectable signal in response to the interaction of the polypeptide with the compound; and   determining whether the compound interacts with and inhibits an activity of the polypeptide by detecting the presence or absence of a signal generated from the interaction of the compound with the polypeptide.   
   
   
       19 - 20 . (canceled) 
   
   
       21 . The antagonist of  claim 14  selected from the group consisting of a small organic molecule, a peptide, a polypeptide, and an antibody. 
   
   
       22 . The antagonist of  claim 14 , wherein the activity of the polypeptide is inhibited by disruption of the formation of a methionyl tRNA synthetase:methionyl adenylate complex. 
   
   
       23 . The antagonist of  claim 14 , wherein the activity of the polypeptide is inhibited by inhibition of tRNA esterification. 
   
   
       24 . The antagonist of  claim 14 , wherein the antagonist inhibits methionyl acylation. 
   
   
       25 . The antagonist of  claim 14 , wherein the antagonist inhibits the activity of the polypeptide by binding the polypeptide. 
   
   
       26 . The antagonist of  claim 14 , wherein the antagonist inhibits the activity of the polypeptide by interfering with expression of the polypeptide. 
   
   
       27 . The antagonist of  claim 26 , wherein the antagonist is an antisense molecule. 
   
   
       28 . The antagonist of  claim 14 , wherein the antagonist is a substrate for methionyl tRNA synthetase. 
   
   
       29 . The method of  claim 18 , wherein the compound is selected from the group consisting of a small organic molecule, a peptide, a polypeptide, and an antibody. 
   
   
       30 . A method for identifying compounds which inhibit an activity of the polypeptide represented by SEQ ID NO: 2 or 4, the method comprising:
 contacting a cell expressing on the surface thereof a substrate for binding the polypeptide, said substrate being associated with a second component capable of providing a detectable signal in response to the binding of a compound to the substrate, with a compound to be screened under conditions to permit binding to the substrate; and   determining whether the compound binds to the substrate by detecting the presence or absence of a signal generated from the interaction of the compound with the substrate.   
   
   
       31 . The method of  claim 30 , wherein the substrate is methionyl adenylate. 
   
   
       32 . The method of  claim 30 , wherein the compound is selected from the group consisting of a small organic molecule, a peptide, a polypeptide, and an antibody. 
   
   
       33 . The method of  claim 30 , wherein the method comprises further contacting the cell with the polypeptide in the presence of the compound to be screened. 
   
   
       34 . The method of  claim 33 , wherein the method comprises further determining whether the compound competitively inhibits activity of the polypeptide. 
   
   
       35 . The method of  claim 33 , wherein the compound is a variant of tRNA synthetase. 
   
   
       36 . A method of screening drugs to identify those which interfere with the interaction of the methionyl tRNA synthetase represented by SEQ ID NO: 2 or 4, wherein the method comprises measuring enzyme activity by the full aminoacylation reaction or the partial PPi/ATP exchange reaction. 
   
   
       37 . The method of  claim 36 , wherein the method comprises measuring enzyme activity by full aminoacylation reaction and wherein each drug is characterized as to whether the drug decreases aminoacylation relative to aminoacylation in the absence of the drug. 
   
   
       38 . The method of  claim 36 , wherein the method comprises measurement of enzyme activity by partial PPi/ATP exchange reaction and wherein each drug is characterized as to whether the drug decreases PPi/ATP exchange relative to PPi/ATP exchange in the absence of the drug. 
   
   
       39 . The method of  claim 36 , wherein the drugs are independently selected from the group consisting of a small organic molecule, a peptide, a polypeptide, and an antibody.