Compositions and methods for identifying inhibitors of RNA-target molecule interactions are provided as well as identifying inhibitors that block the role of tRNA in protein synthesis. The methods involve forming a mixture comprising a tRNA fragment molecule containing a modified nucleotide, a target molecule capable of binding to the tRNA fragment, and a test compound. The mixture is incubated under conditions that allow binding of the tRNA and the target molecule in the absence of the test compound. Assays can then be performed that detect whether or not the test compound inhibits the binding of the tRNA molecule and the target molecule. High throughput assays are also provided.