title: Origins of tmRNA: the missing link in the birth of protein synthesis?
abstract: The RNA world hypothesis refers to the early period on earth in which RNA was central in assuring both genetic continuity and catalysis. The end of this era coincided with the development of the genetic code and protein synthesis, symbolized by the apparition of the first non-random messenger RNA (mRNA). Modern transfer-messenger RNA (tmRNA) is a unique hybrid molecule which has the properties of both mRNA and transfer RNA (tRNA). It acts as a key molecule during trans-translation, a major quality control pathway of modern bacterial protein synthesis. tmRNA shares many common characteristics with ancestral RNA. Here, we present a model in which proto-tmRNAs were the first molecules on earth to support non-random protein synthesis, explaining the emergence of early genetic code. In this way, proto-tmRNA could be the missing link between the first mRNA and tRNA molecules and modern ribosome-mediated protein synthesis.
authors.affiliation: Université de Rennes 1, CNRS UMR 6290 IGDR, Translation and Folding Team, 35042 Rennes cedex, France.
authors.forename: Kevin
authors.initials: K
authors.lastname: Macé
authors.affiliation: Université de Rennes 1, CNRS UMR 6290 IGDR, Translation and Folding Team, 35042 Rennes cedex, France Institut Universitaire de France reynald.gillet@univ-rennes1.fr.
authors.forename: Reynald
authors.initials: R
authors.lastname: Gillet
mesh_terms: D005815:Genetic Code; D008954:Models, Biological; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; C096222:tmRNA