Development of an advanced polysome display system dependent on a specific protein-RNA motif interaction.

The ribosome display system is a very powerful too for in vitro screening of mRNAs that encode proteins (or peptides) with specific (known and unknown) functions. The ribosome display system depends on the stability of ribosome-mRNA complexes that have been achieved by the removal of a stop codon. An additional interaction we employed was between tandem fused MS2 coat protein (MSp) dimer and the RNA of its specific motif called a "C-variant" (or "Cv"). The MSp dimer and the Cv were placed at the N-terminal end of a nascent protein translated in vitro and the 5'-end of its mRNA, that might circularize the polysome complex and, as a result, further stabilize the ribosome-mRNA complex. The selectivity of mRNAs after selection was increased 2-fold by the introduction of the interaction between the MSp dimer and Cv.