caa a22 4500 445821361 CHVBK 20180317145245.0 cr unu---uuuuu 170323e20110401xx s 000 0 eng 10.1007/s00239-011-9440-9 doi (NATIONALLICENCE)springer-10.1007/s00239-011-9440-9 The Presence in tRNA Molecule Sequences of the Double Hairpin, an Evolutionary Stage Through Which the Origin of this Molecule is Thought to have Passed [Elektronische Daten] [Sergio Branciamore, Massimo Di Giulio] We analyse 6,810 tRNAs, calculating the free energy of the corresponding double hairpin and ‘cigar' secondary structures, for which we find a high thermodynamic and statistical significance. We also analyse these tRNAs for similarity and complementarity of their 5′ and 3′ halves or segments of them in intra-and inter-molecular comparisons. We find very clear signs that the two halves of tRNAs had an evident evolutionary relationship, although it is not totally clear whether this was a relationship of homology or complementarity between the 5′ and 3′ halves of tRNAs, even if there is strong evidence in favour of the homology hypothesis. Overall, these data favour models for the origin of the tRNA molecule postulating that a duplication event involving a hairpin structure as a precursor was involved in the origin of this molecule. Moreover, we interpret these results and favour the hypothesis that sees the assembly of two hairpin structures sharing a homology relationship as the intermediate evolutionary stage preceding the appearance of the cloverleaf structure of tRNA. Springer Science+Business Media, LLC, 2011 Transitional stages nationallicence Intermediate stages nationallicence Evolutionary precursors nationallicence Free energy (Δ G ) nationallicence Secondary RNA structures nationallicence Models for tRNA origin nationallicence Macroevolution nationallicence Branciamore Sergio Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, 91010, Duarte, CA, USA aut Di Giulio Massimo Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, 91010, Duarte, CA, USA aut Journal of Molecular Evolution Springer-Verlag 72/4(2011-04-01), 352-363 0022-2844 72:4<352 2011 72 239 https://doi.org/10.1007/s00239-011-9440-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00239-011-9440-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Branciamore Sergio Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, 91010, Duarte, CA, USA aut NATIONALLICENCE 700 1- Di Giulio Massimo Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, 91010, Duarte, CA, USA aut NATIONALLICENCE 773 0- Journal of Molecular Evolution Springer-Verlag 72/4(2011-04-01), 352-363 0022-2844 72:4<352 2011 72 239 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer