A tmRNA liberates a mRNA from a stalled ribosome. To accomplish this part of the tmRNA is used as a reading frame that ends in a translation stop signal. The broken mRNA is replaced in the ribosome by the tmRNA and translation of the tmRNA leads to addition of a proteolysis tag to the incomplete protein enabling recognition by a protease. Recently a number of permuted tmRNAs genes have been found encoded in two parts. TmRNAs have been identified in eubacteria and some chloroplasts but are absent from archeal and Eukaryote nuclear genomes.