Abstract
Theoretical minimal RNA rings attempt to mimick life’s primitive RNAs. At most 25 22-nucleotide-long RNA rings code once for each biotic amino acid, a start and a stop codon and form a stem-loop hairpin, resembling consensus tRNAs. We calculated, for each RNA ring’s 22 potential splicing positions, similarities of predicted secondary structures with tRNA vs. rRNA secondary structures. Assuming rRNAs partly derived from tRNA accretions, we predict positive associations between relative secondary structure similarities with rRNAs over tRNAs and genetic code integration orders of RNA ring anticodon cognate amino acids. Analyses consider for each secondary structure all nucleotide triplets as potential anticodon. Anticodons for ancient, chemically inert cognate amino acids are most frequent in the 25 RNA rings. For RNA rings with primordial cognate amino acids according to tRNA-homology-derived anticodons, tRNA-homology and coding sequences coincide, these are separate for predicted cognate amino acids that presumably integrated late the genetic code. RNA ring secondary structure similarity with rRNA over tRNA secondary structures associates best with genetic code integration orders of anticodon cognate amino acids when assuming split anticodons (one and two nucleotides at the spliced RNA ring 5′ and 3′ extremities, respectively), and at predicted anticodon location in the spliced RNA ring’s midst. Results confirm RNA ring homologies with tRNAs and CDs, ancestral status of tRNA half genes split at anticodons, the tRNA-rRNA axis of RNA evolution, and that single theoretical minimal RNA rings potentially produce near-complete proto-tRNA sets. Hence genetic code pre-existence determines 25 short circular gene- and tRNA-like RNAs. Accounting for each potential splicing position, each RNA ring potentially translates most amino acids, realistically mimicks evolution of the tRNA-rRNA translation machinery. These RNA rings ‘of creation’ remind the uroboros’ (snake biting its tail) symbolism for creative regeneration.
Similar content being viewed by others
References
Agmon I (2009) The dimeric proto-ribosome: structural details and possible implications on the origin of life. Int J Mol Sci 10:2921–2934
Ahmed A, Frey G, Michel CJ (2007) Frameshift signals in genes associated with circular code. Silico Biol 7:155–168
Ahmed A, Frey G, Michel CJ (2010) Essential molecular functions associated with the circular code evolution. J Theor Biol 264:613–622
Amzallag GN (2016) The serpent as a symbol of primeval Yahvism. Semitica 58:207–236
Arquès DG, Michel CJ (1996) A complementary circular code in the protein coding genes. J Theor Biol 182:45–58
Barrett SP, Salzman J (2016) Circular RNAs: analysis, expression and potential functions. Development 143:1838–1847
Barthélémy RM, Seligmann H (2016) Cryptic tRNAs in chaetognath mitochondrial genomes. Comput Biol Chem 62:119–132
Bartonek L, Zagrovic B (2017) mRNA/protein sequence complementarity and its determinants: the impact of affinity scales. PLoS Comput Biol 13:e1005648
Bieri P, Greber BJ, Ban N (2018) High-resolution structures of mitochondrial ribosomes and their functional implications. Curr Op Struct Biol 49:44–53
Bloch DP, McArthur B, Widdowson R, Spector D, Guimarães RC, Smith J (1983) tRNA-rRNA sequence homologies: evidence for a common evolutionary origin? J Mol Evol 19:420–428
Bloch DP, McArthur B, Widdowson R, Spector D, Guimarães RC, Smith J (1984) tRNA-rRNA sequence homologies: a model for the origin of a common ancestral molecule, and prospects for its reconstruction. Orig Life 14:571–578
Bloch DP, McArthur B, Guimarães RC, Smith J, Staves MP (1989) tRNA-rRNA sequence matches from inter- and intraspecies comparisons suggest common origins for the two RNAs. Braz J Med Biol Res 22:931–944
Branciamore S, Di Giulio M (2011) 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. J Mol Evol 72:352–363
Caetano-Anollés D, Caetano-Anollés G (2016) Piecemeal buildup of the genetic code, ribosomes, genomes from primordial tRNA building blocks. Life (Basel) 6:e43
Caetano-Anollés G, Sun F-J (2014) The natural history of transfer RNA and its interactions with the ribosome. Front Genet 5:127
Carrodeguas JA, Kobayashi R, Lim SE, Copeland WC, Bogenhagen DF (1999) The accessory subunit of Xenopus laevis mitochondrial DNA polymerase gamma increases processivity of the catalytic subunit of human DNA polymerase gamma and is related to class II aminoacyl-tRNA synthetases. Mol Cell Biol 19:4039–4046
Chaley MB, Korotkov EV, Phoenix DA (1999) Relationships among isoacceptor tRNAs seem to support the co-evolution theory of the origin of the genetic code. J Mol Evol 48:168–177
Chan PP, Cozen AE, Lowe TM (2011) Discovery of permuted and recently split transfer RNAs in Archaea. Genome Biol 12:R38
Chrzanowska-Lightowlers ZF, Rorbach J, Minczuk M (2017) Human mitochondrial ribosomes can switch structural tRNAs-but when and why? RNA Biol 14:1668–1671
Cuesta JA, Manrubia S (2017) Enumerating secondary structures and structural moieties for circular RNAs. J Theor Biol 419:375–382
Danan M, Schwartz S, Edelheit S, Sorek R (2012) Transcriptome-wide discovery of circular RNAs in Archaea. Nucleic Acids Res 40:3131–3142
Demongeot J (1978) Sur la possibilité de considérer le code génétique comme un code à enchaînement. Revue de Biomaths 62:61–66
Demongeot J, Besson J (1983) Genetic-code and cyclic codes. Comptes R Acad Sci III Life Sci 296:807–810
Demongeot J, Moreira A (2007) A possible circular RNA at the origin of life. J Theor Biol 249:314–324
Demongeot J, Glade N, Moreira A, Vial L (2009) RNA relics and origin of life. Int J Mol Sci 10:3420–3441
Demongeot J, Norris V (2019) Emergence of a “cyclosome” in a primitive network capable of building “infinite” proteins. Life (Basel) 9:e51
Demongeot J, Seligmann H (2019a) Theoretical minimal RNA rings recapitulate the order of the genetic code’s codon-amino acid assignments. J Theor Biol 471:108–116
Demongeot J, Seligmann H (2019b) More pieces of ancient than recent theoretical minimal proto-tRNA-like RNA rings in genes coding for tRNA synthetases. J Mol Evol 87:152–174
Demongeot J, Seligmann H (2019c) Spontaneous evolution of circular codes in theoretical minimal RNA rings. Gene 705:95–102
Demongeot J, Seligmann H (2019d) Bias for 3′-dominant codon directional asymmetry in theoretical minimal RNA rings. J Comput Biol. https://doi.org/10.1089/cmb.2018.0256
Demongeot J, Seligmann H (2019e) Theoretical minimal RNA rings designed according to coding constraints mimick deamination gradients. Naturwissenschaften 106:44
Di Giulio M (1995) Was it an ancient gene codifying for a hairpin RNA that, by means of direct duplication, gave rise to the primitive tRNA molecule? J Theor Biol 177:95–101
Di Giulio M (1999) The non-monophyletic origin of the tRNA molecule. J Theor Biol 197:403–414
Di Giulio M (2006) The non-monophyletic origin of the tRNA molecule and the origin of genes only after the evolutionary stage of the last universal common ancestor (LUCA). J Theor Biol 240:343–352
Di Giulio M (2008a) The split genes of Nanorchaeum equitans are an ancestral character. Gene 421:20–26
Di Giulio M (2008b) Transfer RNA genes in pieces are an ancestral character. EMBO Rep 9:820
Di Giulio M (2009a) A comparison among the models proposed to explain the origin of the tRNA molecule: a synthesis. J Mol Evol 69:1–9
Di Giulio M (2009b) Formal proof that the split genes of tRNAs of Nanoarchaeum equitans are an ancestral character. J Mol Evol 69:505–511
Di Giulio M (2012a) The origin of the tRNA molecule: independent data favor a specific model of its evolution. Biochimie 94:1464–1466
Di Giulio M (2012b) The ‘recently’ split transfer RNA genes may be close to merging the two halves of the tRNA rather than having just separated them. J Theor Biol 310:1–2
Di Giulio M (2013) A polyphyletic model for the origin of tRNAs has more support than a monophyletic model. J Theor Biol 318:124–128
Diener TO (1989) Circular RNAs: relics of precellular evolution? Proc Natl Acad Sci USA 86:9370–9374
Dila G, Michel CJ, Poch O, Ripp R, Thompson JD (2018) Evolutionary conservation and functional implications of circular code motifs in eukaryotic genomes. Biosystems 175:57–74
Dong R, Ma XK, Li GW, Yang L (2018) CIRCpedia v2: an updated database for comprehensive circular RNA nnotation and expression comparison. Genomics Proteom Bioinf 16:226–233
Eigen M, Winkler-Oswatitsch R (1981a) Transfer-RNA: the early adaptor. Naturwissenschaften 68:217–228
Eigen M, Winkler-Oswatitsch R (1981b) Transfer-RNA, an early gene? Naturwissenschaften 68:282–292
El Houmami N, Seligmann H (2017) Evolution of nucleotide punctuation marks: from structural to linear signals. Front Genetics 8:36
Fan L, Sanschagrin PC, Kaguni LS, Kuhn LA (1999) The accessory subunit of mtDNA polymerase shares structural homology with aminoacyl–tRNA synthetases: implications for a dual role as a primer recognition factor and processivity clamp. Proc Natl Acad Sci U S A 96:9527–9532
Farias ST, Rêgo TG, José MV (2014) Origin and evolution of the peptidyl transferase center from proto-tRNAs. FEBS Open Bio 4:175–178
Farias ST, Rêgo TG, José MV (2019) Origin of the 16S ribosomal molecular from ancestral tRNAs. Science 1:8
Faure E, Barthélémy RM (2018) True tRNA punctuation: specific conserved positions of stop and start codons in mitochondrial tRNA genes link transcription and translation. Chapter 1 in: Mitochondrial DNA- new insights, Seligmann H and Warthi G (eds), InTech, Rijeky
Fontecilla-Camps JC (2014) The stereochemical basis of the genetic code and the (Mostly) autotrophic origin of life. Life 4:1013–1025
Fujishima K, Sugahara J, Tomita M, Kanai A (2008) Sequence evidence in the archaeal genomes that tRNAs emerged through the combination of ancestral genes as 5′ and 3′ tRNA halves. PLoS ONE 3:e1622
Giulio Di et al (2014) The split genes of Nanoarchaeum equitans have not originated in its lineage and have been merged in another Nanoarchaeota: a reply to Podar. J Theor Biol 349:167–169
Guimarães RC (2011) Metabolic basis for the self-referential genetic code. Orig Life Evol Biosph 41:357–371
Guimarães RC (2014) Essentials in the life process indicated by the self-referential genetic code. Orig Life Evol Biosph 44:269–277
Guimarães RC (2015) The self-referential genetic code is biologic and includes the error minimization property. Orig Life Evol Biosph 45:69–75
Guimarães RC (2017) Self-referential encoding on modules of anticodon pairs—roots of the biological flow system. Life 7:16
Guimarães RC, Moreira CH, de Farias ST (2008) A self-referential model for the formation of the genetic code. Theory Biosci 127:249–270
Han DX, Wang HY, Ji ZL (2010) Amino acid homochirality may be linked to the origin of phosphate-based life. J Mol Evol 70:577–582
Hartman H (1975a) Speculations on the evolution of the genetic code. Origins Life Biosph 6:423–427
Hartman H (1975b) Speculations on the origin and evolution of metabolism. J Mol Evol 40:541–544
Hartman H (1978) Speculations on the evolution of the genetic code II. Origins Life Biosph 9:133–136
Hartman H (1995) Speculations on the origin of the genetic code. J Mol Evol 40:541–544
Hartman H, Smith TF (2014) The evolution of the ribosome and the genetic code. Life (Basel) 4:227–249
Hecht A, Glasgow J, Jaschke PR, Bawazer LA, Munson MS, Cochran JR, Endy D, Salit S (2017) Measurements of translation initiation from all 64 codons in E. coli. Nucleic Acids Res 45:3615–3626
Higgs PG, Pudritz RE (2009) A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code. Astrobiology 9:483–490
Hixson JE, Wong TW, Clayton DA (1986) Both the conserved stem-loop and divergent 5′-flanking sequences are required for initiation at the human mitochondrial origin of light-strand DNA replication. J Biol Chem 261:2384–2390
Hofacker IL, Stadler PF (2006) Memory efficient foding algorithms for circular RNA secondary structures. Bioinformatics 22:1172–1176
Huang S, Yang B, Chen BJ, Bliim N, Ueberham U, Arendt T, Janitz M (2017) The emerging role of circular RNAs in transcriptome regulation. Genomics 109:401–407
Johnson DBF, Wang L (2010) Imprints of the genetic code in the ribosome. Proc Natl Acad Sci USA 107:8298–8303
Jühling F, Pütz J, Florentz C, Stadler PF (2012) Armless mitochondrial tRNAs in Enoplea (Nematoda). RNA Biol 9:1161–1166
Jühling T, Duchardt-Ferner E, Bonin S, Wöhnert J, Pütz J, Florentz C, Betat H, Sauter C, Mörl M (2018) Small but large enough: structural properties of armless mitochondrial tRNAs from the nematode Romanomermis culicivorax. Nucleic Acids Res 46:9170–9180
Kitadai N, Maruyama S (2018) Origins of building blocks of life: a review. Geosci Front 9:1117–1153
Koonin EV (2017) Frozen accident pushing 50: stereochemistry, expansion, and chance in the evolution of the genetic code. Life (Basel) 7:22
Krishnan NM, Seligmann H, Raina SZ, Pollock DD (2004a) Detecting gradients of asymmetry in site-specific substitutions in mitochondrial genomes. DNA Cell Biol 23:707–714
Krishnan NM, Seligmann H, Raina SZ, Pollock DD (2004b) Phylogenetic analyses detect site-specific perturbations in asymmetric mutation gradients. Curr Comput Mol Biol 2004:266–267
Lasda E, Parker R (2014) Circular RNAs: diversity of form and function. RNA 20:1829–2842
Lathe R (2004) Fast tidal cycling and the origin of life. Icarus 168:18–22
Li X, Yang L, Chen L-L (2018) The biogenesis, functions and challenges of circular RNAs. Mol Cell 71:428–442
Maizels N, Weiner AM (1994) Phylogeny from function: evidence from the molecular fossil record that tRNA originated in replication, not translation. Proc Natl Acad Sci USA 91:6729–6734
Michel CJ (2012) Circular code motifs in transfer RNAs. Comput Biol Chem 45:17–29
Michel CJ (2013) Circular code motifs in transfer and 16S ribosomal RNAs: a possible translation code in genes. Comput Biol Chem 37:24–37
Michel CJ, Seligmann H (2014) Bijective transformation circular codes and nucleotide exchanging RNA transcription. Biosystems 118:39–50
Möller W, Janssen GM (1990) Transfer RNAs for primordial amino acids contain remnants of a primitive code at position 3 to 5. Biochimie 72:361–368
Nicolet BP, Engels S, Aglialoro F, van den Akker E, von Lindern M, Wolkers MC (2018) Circular RNA expression in human hematopoietic cells is widespread and cell-type specific. Nucleic Acids Res 46:8168–8180
Ostrovskii VE, Kadyshevich EA (2011) Mitosis and DNA replication and life origination hydrate hypotheses: common physical and chemical grounds. In DNA replication-current advances, Seligmann H (ed), chapter 4, In Tech, Rijeky, p 76-114
Ostrovskii VE, Kadyshevich EA (2012) Life origination hydrate hypothesis (LOH-hypothesis). Life 2:135–164
Pelc SR (1965) Correlation between coding-triplets and amino acids. Nature 207:597–599
Pelc SR, Welton MGE (1966) Stereochemical relationship between coding triplets and amino-acids. Nature 209:868–870
Randau L, Calvin K, Hall M, Yuan J, Podar M, Li H, Söll D (2005a) The heteromeric Nanoarchaeum equitans splicing endonuclease cleaves noncanonical bulge-helix-bulge motifs of joined tRNA halves. Proc Natl Acad Sci USA 102:17934–17939
Randau L, Münch R, Hohn MJ, Jahn D, Söll D (2005b) Nanoarchaeum equitans creates functional tRNAs from separate genes of their 5′- and 3′-halves. Nature 433:537–541
Randau L, Pearson M, Söll D (2005c) The complete set of tRNA species in Nanoarchaeun equitans. FEBS Lett 579:2945–2947
Root-Bernstein R (2007) Simultaneous origin of homochirality, the genetic code and its directionality. BioEssays 29:689–698
Root-Bernstein M, Root-Bernstein R (2015) The ribosome as a missing link in the evolution of life. J Theor Biol 367:130–158
Root-Bernstein R, Root-Bernstein ME (2016) The ribosome as a missing link in prebiotic evolution II: ribosomes encode ribosomal proteins that bind to common regions of their own mRNAs and rRNAs. J Theor Biol 397:115–127
Root-Bernstein R, Kim Y, Sanjay A, Burton ZF (2016) tRNA evolution from the proto-tRNA minihelix world. Transcription 19:153–163
Sablok G, Zhao H, Sun X (2016) Pant circular RNAs (circRNAs): transcriptional regulation beyond miRNAs in plants. Mol Plant 9:192–194
Seligmann H (2008) Hybridization between mitochondrial heavy strand tDNA and expressed light strand tRNA modulates the function of heavy strand tDNA as light strand replication origin. J Mol Biol 379:188–199
Seligmann H (2010) Mitochondrial tRNAs as light strand replication origins: similarity between anticodon loops and the loop of the light strand replication origin predicts initiation of DNA replication. Biosystems 99:85–93
Seligmann H (2011) Mutation patterns due to converging mitochondrial replication and transcription increase lifespan, and cause growth rate-longevity tradeoffs. DNA Replication-Current Advances, Seligmann H. (ed.), In Tech, book chapter 6: 151-80
Seligmann H (2012a) Overlapping genes coded in the 3′-to-5′-direction in mitochondrial genes and 3′-to-5′ polymerization of non-complementary RNA by an ‘invertase’. J Theor Biol 315:38–52
Seligmann H (2012b) Replicational mutation gradients, dipole moments, nearest neighbour effects and DNA polymerase gamma fidelity in human mitochondrial genomes. In: Stuart D (ed) The mechanisms of DNA replication. Springer, New York
Seligmann H (2012c) Coding constraints modulate chemically spontaneous mutational replication gradients in mitochondrial genomes. Curr Genomics 13:37–54
Seligmann H (2013a) Systematic asymmetric nucleotide exchanges produce human mitochondrial RNAs cryptically encoding for overlapping protein coding genes. J Theor Biol 324:1–20
Seligmann H (2013b) Polymerization of non-complementary RNA: systematic symmetric nucleotide exchanges mainly involving uracil produce mitochondrial RNA transcripts coding for cryptic overlapping genes. Biosystems 111:156–174
Seligmann H (2013c) Triplex DNA:RNA, 3′-to-5′ inverted RNA and protein coding in mitochondrial genomes. J Comput Biol 20:660–671
Seligmann H (2013d) Pocketknife tRNA hypothesis: anticodons in mammal mitochondrial tRNA side-arm loops translate proteins? Biosystems 113:165–176
Seligmann H (2014a) Mitochondrial swinger replication: DNA replication systematically exchanging nucleotides and short 16S ribosomal DNA swinger inserts. Biosystems 125:22–31
Seligmann H (2014b) Species radiation by DNA replication that systematically exchanges nucleotides? J Theor Biol 363:216–222
Seligmann H (2014c) Putative anticodons in mitochondrial tRNA sidearm loops: Pocketknife tRNAs? J Theor Biol 340:155–163
Seligmann H (2015a) Systematic exchanges between nucleotides: genomic swinger repeats and swinger transcription in human mitochondria. J Theor Biol 384:70–77
Seligmann H (2015b) Swinger RNAs with sharp switches between regular transcription and transcription systematically exchanging ribonucleotides: case studies. Biosystems 135:1–8
Seligmann H (2016a) Swinger RNA self-hybridization and mitochondrial non-canonical swinger transcription, transcription systematically exchanging nucleotides. J Theor Biol 399:84–91
Seligmann H (2016b) Sharp switches between regular and swinger mitochondrial replication: 16S rDNA systematically exchanging nucleotides A↔T+C↔G in the mitogenome of Kamimuria wangi. Mitochondrial DNA A DNA Mapping Seq Anal 27:2440–2446
Seligmann H (2016c) Translation of mitochondrial swinger RNAs according to tri-, tetra- and pentacodons. Biosystems 140:38–48
Seligmann H (2018) Protein sequences recapitulate genetic code evolution. Comput Struct Biotechnol J 16:177–189
Seligmann H, Amzallag GN (2002) Chemical interactions between amino acid and RNA: multiplicity of the levels of specificity explains origin of the genetic code. Naturwissenschaften 89:542–551
Seligmann H, Krishnan NM (2006) Mitochondrial replication origin stability and propensity of adjacent tRNA genes to form putative replication origins increase developmental stability in lizards. J Exp Zool B Mol Dev Evol 306:433–449
Seligmann H, Krishnan NM, Rao BJ (2006a) Possible multiple origins of replication in Primate mitochondria: alternative role of tRNA sequences. J Theor Biol 241:321–332
Seligmann H, Krishnan NM, Rao BJ (2006b) Mitochondrial tRNA sequences as unusual replication origins: pathogenic implications for Homo sapiens. J Theor Biol 243:375–385
Seligmann H, Labra A (2014) The relation between hairpin formation by mitochondrial WANCY tRNAs and the occurrence of the light strand replication origin in Lepidosauria. Gene 542:248–257
Seligmann H, Raoult D (2016) Unifying view of stem-loop hairpin RNA as origin of current and ancient parasitic and non-parasitic RNAs, including in giant viruses. Curr Opin Microbiol 31:1–8
Seligmann H, Warthi G (2017) Genetic code optimization for cotranslational protein folding: codon directional asymmetry correlates with antiparallel betasheets, tRNA synthetase classes. Comput Struct Biotechnol J 15:412–424
Seligmann H, Raoult D (2018) Stem-loop RNA hairpins in giant viruses: invading rRNA-like repeats and a template free RNA. Front Microbiol 9:101
Smith TF, Hartman H (2015) The evolution of class II aminoacyl-tRNA synthetases and the first code. FEBS Lett 589:3499–3507
Soma A, Onodera A, Sugahara J, Kanai A, Yachie N, Tomita M, Kawamura F, Sekine Y (2007) Permuted tRNA genes expressed via a circular RNA intermediate in Cyanidioschyzon merolae. Science 318:450–453
Sugahara J, Yachie N, Sekine Y, Soma A, Matsui M, Tomita M, Kanai A (2006) SPLITS: a new program for predicting split and intron-containing tRNA genes at the genome level. Silico Biol 6:411–418
Suzuki H, Kaneko A, Yamamoto T, Nambo M, Hirasawa I, Umehara T, Yoshida H, Park SY, Tamura K (2017) Binding properties of split tRNA to the C-terminal domain of methionyl-tRNA synthetase of Nanoarchaeum equitans. J Mol Evol 84:267–278
Tamura K, Schimmel P (2003) Peptide synthesis with a template-like RNA guide and aminoacyl phosphate adaptors. Proc Natl Acad Sci USA 100:8666–8669
Trifonov EN (1999a) Elucidating sequence codes: three codes for evolution. Ann N Y Acad Sci 870:330–338
Trifonov EN (1999b) Glycine clock: eubacteria first archaea next, protoctista, fungi, planta and animalia at last. Gene Therapy Mol Biol 4:313–322
Trifonov EN (2000) Consensus temporal order of amino acids and evolution of the triplet code. Gene 261:139–151
Trifonov EN (2004) The triplet code from first principles. J Biomol Struct Dyn 22:1–11
Trifonov EN, Bettecken T (1997) Sequence fossils, triplet expansion, and reconstruction of earliest codons. Gene 205:1–6
Warthi G, Seligmann H (2018) Swinger RNAs in the human mitochondrial transcriptome. In: Mitochondrial DNA, Seligmann H and Warthi G eds, InTechOpen
Wende S, Platzer EG, Jühling F, Pütz J, Florentz C, Stadler PF, Mörl M (2014) Biological evidence for the world’s smallest tRNAs. Biochimie 100:151–158
Widmann J, Di Giulio M, Yarus M, Knight R (2005) tRNA creation by hairpin duplication. J Mol Evol 61:524–530
Wolf YI, Koonin EV (2001) Origin of an animal mitochondrial DNA polymerase subunit via lineage-specific acquisition of a glycyl–tRNA synthetase from bacteria of the Thermus-Deinococcus group. Trends Genet 17:431–433
Xia T, SantaLucia J Jr, Burkhard ME, Kierzek R, Schroeder SJ, Jiao X, Cox C, Turner DH (1998) Thermodynamic parameters for an expanded nearest-neighbor model for formation of RNA duplexes with Watson-Crick base pairs. Biochemistry 37:14719–14735
Yarus M (2017) The genetic code and RNA-amino acid affinities. Life (Basel) 7:13
Yarus M, Christian EL (1989) Genetic code origins. Nature 342:349–350
Yarus M, Widmann JJ, Knight R (2009) RNA-amino acid binding: a stereochemical era for the genetic code. J Mol Evol 69:406–429
Zagrovic B, Bartonek L, Polyansky AA (2018) RNA-protein interactions in an unstructured context. FEBS Lett 592:2901–2916
Zuker M (2003) Mfold web server for nucleic acid folding and hybridization prediction. Nucleic Acids Res 31:3406–3415
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Demongeot, J., Seligmann, H. The Uroboros Theory of Life’s Origin: 22-Nucleotide Theoretical Minimal RNA Rings Reflect Evolution of Genetic Code and tRNA-rRNA Translation Machineries. Acta Biotheor 67, 273–297 (2019). https://doi.org/10.1007/s10441-019-09356-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10441-019-09356-w