title: RNA editing and modifications of RNAs might have favoured the evolution of the triplet genetic code from an ennuplet code.
abstract: Here we suggest that the origin of the genetic code, that is to say, the birth of first mRNAs has been triggered by means of a widespread modification of all RNAs (proto-mRNAs and proto-tRNAs), as today observed in the RNA editing and in post-transcriptional modifications of RNAs, which are considered as fossils of this evolutionary stage of the genetic code origin. We consider also that other mechanisms, such as the trans-translation and ribosome frameshifting, could have favoured the transition from an ennuplet code to a triplet code. Therefore, according to our hypothesis all these mechanisms would be reflexive of this period of the evolutionary history of the genetic code.
authors.affiliation: Early Evolution of Life Laboratory, Institute of Biosciences and Bioresources, CNR, Via P. Castellino 111, 80131 Naples, Italy. Electronic address: massimo.digiulio@ibbr.cnr.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Di Giulio
authors.affiliation: Glycobiology Laboratory, Institute of Biosciences and Bioresources, CNR, Via P. Castellino 111, 80131 Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Moracci
authors.affiliation: Glycobiology Laboratory, Institute of Biosciences and Bioresources, CNR, Via P. Castellino 111, 80131 Naples, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Cobucci-Ponzano
mesh_terms: D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D018965:Frameshifting, Ribosomal / Q000235:genetics; D005815:Genetic Code; D006801:Humans; D012313:RNA / Q000378:metabolism*; D017393:RNA Editing / Q000502:physiology*; D012323:RNA Processing, Post-Transcriptional
chemical_list: D012313:RNA
keywords: Genetic code origin; Molecular fossils; Ribosome frameshifting; tmRNA