Transfer-messenger RNA

Truncated mRNAs lacking a stop codon cause the synthesis of incomplete peptide chains and stall translating ribosomes. In bacteria, a ribonucleoprotein complex composed of tmRNA (transfer-messenger RNA), a molecule that combines the functions of tRNA and mRNA, and small protein B (SmpB) rescues stalled ribosomes (Haebel et al., 2004). The dual function of this molecule as both tRNA and mRNA facilitates a trans-translation reaction in which a ribosome can switch between translation of a truncated mRNA and the tag sequence of tmRNA. 

Transfer-messenger RNA tmRNA Mostly found In bacteria... 

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