Closing the circle: replicating RNA with RNA.
Open accessAbstract
How life emerged on this planet is one of the most important and fundamental questions of science.Although nearly all details concerning our origins have been lost in the depths of time, there is compelling evidence to suggest that the earliest life might have exploited the catalytic and self-recognition properties of RNA to survive.If an RNA based replicating system could be constructed in the laboratory, it would be much easier to understand the challenges associated with the very earliest steps in evolution and provide important insight into the establishment of the complex metabolic systems that now dominate this planet.Recent progress into the selection and characterization of ribozymes that promote nucleotide synthesis and RNA polymerization are discussed and outstanding problems in the field of RNA-mediated RNA replication are summarized.C ell division is a fundamental biological process in which genetic information is duplicated and shared between daughter cells.In extant cellular life, DNA serves as the repository of genetic information, but its replication is complicated by the daunting size and complex structural organization of modern genomes.For this reason, multiple enzymes are required to ensure faithful genomic replication in all higher life forms.Notably, simpler replicating systems such as viruses, have smaller genomes and tend to use correspondingly more errorprone replicative machinery (Kunkel and Bebenek 2000;Gago, Elena et al. 2009).Presumably, if the initial organisms on this planet also had small genomes, then the earliest genomic replication could have been a relatively simple and error-prone process compared with the complex replicative strategies of modern life.
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The RNA world hypothesis proposes RNA molecules as precursors to modern life forms consisting of DNAs as carriers of genomes and proteins as molecular machines.
“One of the simplest and most promising is the RNA world hypothesis [1], [6], [7], which proposes RNA molecules as precursors to modern life forms consisting of DNAs as carriers of genomes and proteins as molecular machines.”
From Thermodynamic Basis for the Emergence of Genomes during Prebiotic Evolution (2012) · cites this paper as [6]
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Cites
Tuerk, C., & Gold, L. (1990) · Science · doi:10.1126/science.2200121 · Cited by 10,421 · see citing works
In vitro selection of RNA molecules that bind specific ligands
Ellington, A. D., & Szostak, J. W. (1990) · Nature · doi:10.1038/346818a0 · Cited by 9,845 · see citing works
The Structural Basis of Ribosome Activity in Peptide Bond Synthesis
Nissen, P., Hansen, J., Ban, N., Moore, P. B., & Steitz, T. A. (2000) · Science · doi:10.1126/science.289.5481.920 · Cited by 2,269 · see citing works
Gilbert, W. (1986) · Nature · Cited by 1,941 · see citing works
Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions.
Powner, M. W., Gerland, B., & Sutherland, J. D. (2009) · Nature · doi:10.1038/nature08013 · Cited by 1,383 · see citing works
Selection in vitro of an RNA enzyme that specifically cleaves single-stranded DNA
Robertson, D. L., & Joyce, G. F. (1990) · Nature · doi:10.1038/344467a0 · Cited by 1,331 · see citing works
In Vitro Selection of Functional Nucleic Acids
Wilson, D. S., & Szostak, J. W. (1999) · Annual Review of Biochemistry · doi:10.1146/annurev.biochem.68.1.611 · Cited by 1,209 · see citing works
Crick, F. (1958) · PubMed · Cited by 1,188 · see citing works
Prebiotic chemistry and the origin of the RNA world.
Leslie E., O. (2004) · Critical Reviews in Biochemistry and Molecular Biology · doi:10.1080/10409230490460765 · Cited by 1,124 · see citing works
The antiquity of RNA-based evolution.
Joyce, G. F. (2002) · Nature · doi:10.1038/418214a · Cited by 1,070 · see citing works
MECHANISM AND CONTROL OF TRANSCRIPTION INITIATION IN PROKARYOTES
McClure, W. R. (1985) · Annual Review of Biochemistry · doi:10.1146/annurev.bi.54.070185.001131 · Cited by 1,023 · see citing works
Kunkel, T. A., & Bebenek, K. (2000) · Annual Review of Biochemistry · doi:10.1146/annurev.biochem.69.1.497 · Cited by 1,003 · see citing works
Man-made cell-like compartments for molecular evolution
Tawfik, D. S., & Griffiths, A. D. (1998) · Nature Biotechnology · doi:10.1038/nbt0798-652 · Cited by 960 · see citing works
Isolation of New Ribozymes from a Large Pool of Random Sequences
Bartel, D. P., & Szostak, J. W. (1993) · Science · doi:10.1126/science.7690155 · Cited by 900 · see citing works
Synthesis of long prebiotic oligomers on mineral surfaces.
Ferris, J. P., Hill, A. R., Liu, R., & Orgel, L. E. (1996) · Nature · doi:10.1038/381059a0 · Cited by 865 · see citing works
Kiss (2002) · doi:10.1016/s0092-8674(02)00718-3 · Cited by 816 · see citing works
RNA-catalyzed RNA polymerization: Accurate and general RNA-templated primer extension.
Johnston, W. K., Unrau, P. J., Lawrence, M. S., Glasner, M. E., & Bartel, D. P. (2001) · Science · doi:10.1126/science.1060786 · Cited by 768 · see citing works
Self-citationNon-coding RNAs: lessons from the small nuclear and small nucleolar RNAs
Matera, A. G., Terns, R. M., & Terns, M. P. (2007) · Nature Reviews Molecular Cell Biology · doi:10.1038/nrm2124 · Cited by 752 · see citing works
Self-Sustained Replication of an RNA Enzyme
Lincoln, T. A., & Joyce, G. F. (2009) · Science · doi:10.1126/science.1167856 · Cited by 670 · see citing works
RNA evolution and the origins of life
Joyce, G. F. (1989) · Nature · doi:10.1038/338217a0 · Cited by 658 · see citing works
Borate Minerals Stabilize Ribose
Ricardo, A., Carrigan, M. A., Olcott, A. N., & Benner, S. A. (2004) · Science · doi:10.1126/science.1092464 · Cited by 646 · see citing works
Riboswitches as versatile gene control elements
Tucker, B. J., & Breaker, R. R. (2005) · Current Opinion in Structural Biology · doi:10.1016/j.sbi.2005.05.003 · Cited by 546 · see citing works
Coenzymes as fossils of an earlier metabolic state
White, H. B. (1976) · Journal of Molecular Evolution · doi:10.1007/bf01732468 · Cited by 493 · see citing works
A mechanism for initiating RNA-dependent RNA polymerization
Butcher, S. J., Grimes, J. M., Makeyev, E. V., Bamford, D. H., & Stuart, D. I. (2001) · Nature · doi:10.1038/35065653 · Cited by 489 · see citing works
Modern metabolism as a palimpsest of the RNA world
Benner, S. A., Ellington, A. D., & Tauer, A. (1989) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.86.18.7054 · Cited by 478 · see citing works
Structurally Complex and Highly Active RNA Ligases Derived from Random RNA Sequences
Ekland, E. H., Szostak, J. W., & Bartel, D. P. (1995) · Science · doi:10.1126/science.7618102 · Cited by 422 · see citing works
Protein-primed RNA synthesis by purified poliovirus RNA polymerase
Paul, A. V., BOOM, J. H. V., Filippov, D. V., & Wimmer, E. (1998) · Nature · doi:10.1038/30529 · Cited by 389 · see citing works
The origin of life—a review of facts and speculations
Orgel, L. E. (1998) · Trends in Biochemical Sciences · doi:10.1016/s0968-0004(98)01300-0 · Cited by 361 · see citing works
Structural Basis for the Transition from Initiation to Elongation Transcription in T7 RNA Polymerase
Yin, Y. W., & Steitz, T. A. (2002) · Science · doi:10.1126/science.1077464 · Cited by 352 · see citing works
The Structural Mechanism of Translocation and Helicase Activity in T7 RNA Polymerase
Yin, Y. W., & Steitz, T. A. (2004) · Cell · doi:10.1016/s0092-8674(04)00120-5 · Cited by 337 · see citing works
Wang, Y. (2004) · Nucleic Acids Research · doi:10.1093/nar/gkh271 · Cited by 318 · see citing works
RNA-catalysed nucleotide synthesis
Unrau, P. J., & Bartel, D. P. (1998) · Nature · doi:10.1038/26193 · Cited by 310 · see citing works
Self-citationStudies in prebiotic synthesis
Fuller, W. D., Sanchez, R. A., & Orgel, L. E. (1972) · Journal of Molecular Biology · doi:10.1016/0022-2836(72)90383-x · Cited by 280 · see citing works
An efficient prebiotic synthesis of cytosine and uracil
Robertson, M. P., & Miller, S. L. (1995) · Nature · doi:10.1038/375772a0 · Cited by 272 · see citing works
The RNA world : the nature of modern RNA suggests a prebiotic RNA world
Gesteland, R. F., & Atkins, J. F. (1993) · Cited by 267 · see citing works
Extremely High Mutation Rate of a Hammerhead Viroid
Gago, S., Elena, S. F., Flores, R., & Sanjuán, R. (2009) · Science · doi:10.1126/science.1169202 · Cited by 266 · see citing works
RNA-catalysed RNA polymerization using nucleoside triphosphates
Ekland, E. H., & Bartel, D. P. (1996) · Nature · doi:10.1038/382373a0 · Cited by 250 · see citing works
In vitro selection of an allosteric ribozyme that transduces analytes to amplicons
Robertson, M. P., & Ellington, A. D. (1999) · Nature Biotechnology · doi:10.1038/5236 · Cited by 241 · see citing works
Uracil-DNA glycosylase acts by substrate autocatalysis
Dinner, A. R., Blackburn, G. M., & Karplus, M. (2001) · Nature · doi:10.1038/35099587 · Cited by 228 · see citing works
RNase P RNAs from some Archaea are catalytically active
Pannucci, J. A., Haas, E. S., Hall, T. A., Harris, J. K., & Brown, J. W. (1999) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.96.14.7803 · Cited by 221 · see citing works
Structure-Function Relationships Among RNA-Dependent RNA Polymerases
Ng, K. K.-S., Arnold, J. J., & Cameron, C. E. (2007) · Current topics in microbiology and immunology · doi:10.1007/978-3-540-75157-1_7 · Cited by 215 · see citing works
Directed evolution by in vitro compartmentalization
Miller, O. J., Bernath-Levin, K., Agresti, J. J., Amitai, G., Kelly, B. T., Mastrobattista, E., Taly, V., Magdassi, S., Tawfik, D. S., & Griffiths, A. D. (2006) · Nature Methods · doi:10.1038/nmeth897 · Cited by 213 · see citing works
Selection of an improved RNA polymerase ribozyme with superior extension and fidelity
Zaher, H. S., & Unrau, P. J. (2007) · RNA · doi:10.1261/rna.548807 · Cited by 203 · see citing works
Self-citationSigma and RNA Polymerase: An On-Again, Off-Again Relationship?
Mooney, R. A., Darst, S. A., & Landick, R. C. (2005) · Molecular Cell · doi:10.1016/j.molcel.2005.10.015 · Cited by 161 · see citing works
Monnard, P.-A., Kanavarioti, A., & Deamer, D. W. (2003) · Journal of the American Chemical Society · doi:10.1021/ja036465h · Cited by 159 · see citing works
Initiation of viral RNA-dependent RNA polymerization
van Dijk, A. A., Makeyev, E. V., & Bamford, D. H. (2004) · Journal of General Virology · doi:10.1099/vir.0.19731-0 · Cited by 154 · see citing works
Basis for Structural Diversity in Homologous RNAs
Krasilnikov, A. S., Xiao, Y., Pan, T., & Mondragón, A. (2004) · Science · doi:10.1126/science.1101489 · Cited by 143 · see citing works
RNA polymerase: the vehicle of transcription
Borukhov, S. I., & Nudler, E. (2008) · Trends in Microbiology · doi:10.1016/j.tim.2007.12.006 · Cited by 140 · see citing works
Crystal Structure of the Catalytic Core of an RNA-Polymerase Ribozyme
Shechner, D. M., Grant, R. A., Bagby, S. C., Koldobskaya, Y., Piccirilli, J. A., & Bartel, D. P. (2009) · Science · doi:10.1126/science.1174676 · Cited by 136 · see citing works
Bartel, D. P., & Unrau, P. J. (1999) · Trends in Cell Biology · doi:10.1016/s0962-8924(99)01669-4 · Cited by 134 · see citing works
Self-citationThe secondary structure and sequence optimization of an RNA ligase ribozyme
Ekland, E. H., & Bartel, D. P. (1995) · Nucleic Acids Research · doi:10.1093/nar/23.16.3231 · Cited by 127 · see citing works
Generation of Long RNA Chains in Water
Costanzo, G., Pino, S., Ciciriello, F., & Mauro, E. D. (2009) · Journal of Biological Chemistry · doi:10.1074/jbc.m109.041905 · Cited by 126 · see citing works
Triple-helix structure in telomerase RNA contributes to catalysis
Qiao, F., & Cech, T. R. (2008) · Nature Structural & Molecular Biology · doi:10.1038/nsmb.1420 · Cited by 125 · see citing works
Self-assembly of a group I intron from inactive oligonucleotide fragments
Hayden, E. J., & Lehman, N. (2006) · Chemistry & Biology · doi:10.1016/j.chembiol.2006.06.014 · Cited by 117 · see citing works
Cross-catalytic replication of an RNA ligase ribozyme.
Kim, D.-E., & Joyce, G. F. (2004) · Chemistry and Biology · doi:10.1016/j.chembiol.2004.08.021 · Cited by 112 · see citing works
The Structural Basis of Ribozyme-Catalyzed RNA Assembly
Robertson, M. P., & Scott, W. G. (2007) · Science · doi:10.1126/science.1136231 · Cited by 111 · see citing works
Structure and function of archaeal RNA polymerases
Werner, F. (2007) · Molecular Microbiology · doi:10.1111/j.1365-2958.2007.05876.x · Cited by 108 · see citing works
Madison‐Antenucci, S., Grams, J. M., & Hajduk, S. L. (2002) · Cell · doi:10.1016/s0092-8674(02)00653-0 · Cited by 106 · see citing works
A complex ligase ribozyme evolved in vitro from a group I ribozyme domain
Jaeger, L., Wright, M. C., & Joyce, G. F. (1999) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.96.26.14712 · Cited by 102 · see citing works
Prebiotic Synthesis of Nucleotides
Zubay, G., & Mui, T. P. (2001) · Origins of Life and Evolution of Biospheres · doi:10.1023/a:1006722423070 · Cited by 98 · see citing works
De novo synthesis and development of an RNA enzyme
Ikawa, Y., Tsuda, K., Matsumura, S., et al. (2004) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0405886101 · Cited by 92 · see citing works
Replication of RNA by the DNA-dependent RNA polymerase of phage T7
Konarska, M. M., & Sharp, P. A. (1989) · Cell · doi:10.1016/0092-8674(89)90917-3 · Cited by 85 · see citing works
Hayden, E. J., von Kiedrowski, G., & Lehman, N. (2008) · Angewandte Chemie International Edition · doi:10.1002/anie.200802177 · Cited by 82 · see citing works
Reconstituting Bacterial RNA Repair and Modification in Vitro
Chan, C. M., Zhou, C., & Huang, R. H. (2009) · Science · doi:10.1126/science.1179480 · Cited by 73 · see citing works
Ricardo, A., & Szostak, J. W. (2009) · Scientific American · doi:10.1038/scientificamerican0909-54 · Cited by 72 · see citing works
Evolutionary origins and directed evolution of RNA
Ellington, A. D., Chen, X., Robertson, M. P., & Syrett, H. A. (2008) · The International Journal of Biochemistry & Cell Biology · doi:10.1016/j.biocel.2008.08.015 · Cited by 68 · see citing works
Isolation of Fast Purine Nucleotide Synthase Ribozymes
Lau, M. W. L., Cadieux, K. E. C., & Unrau, P. J. (2004) · Journal of the American Chemical Society · doi:10.1021/ja045387a · Cited by 63 · see citing works
Self-citationBacteriophage φ6 RNA-dependent RNA Polymerase
Laurila, M. R. L., Makeyev, E. V., & Bamford, D. H. (2002) · Journal of Biological Chemistry · doi:10.1074/jbc.m111220200 · Cited by 61 · see citing works
Structure and Function of Eukaryotic Ribonuclease P RNA
Marquez, S. M., Chen, J. J. ‐., Evans, D., & Pace, N. R. (2006) · Molecular Cell · doi:10.1016/j.molcel.2006.09.011 · Cited by 59 · see citing works
Mechanisms of covalent self-assembly of the Azoarcus ribozyme from four fragment oligonucleotides
Draper, W., Hayden, E. J., & Lehman, N. (2007) · Nucleic Acids Research · doi:10.1093/nar/gkm1055 · Cited by 55 · see citing works
Versatile 5′ phosphoryl coupling of small and large molecules to an RNA
Huang, F., & Yarus, M. (1997) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.94.17.8965 · Cited by 51 · see citing works
Emergence of a fast-reacting ribozyme that is capable of undergoing continuous evolution
Voytek, S. B., & Joyce, G. F. (2007) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0707490104 · Cited by 50 · see citing works
The three-dimensional architecture of the class I ligase ribozyme
Bergman, N. H., Lau, N. C., Lehnert, V., Westhof, É., & Bartel, D. P. (2004) · RNA · doi:10.1261/rna.5177504 · Cited by 47 · see citing works
Mechanism and Control of Transcription Initiation in Prokaryotes
McClure, W. (1985) · Annual Review of Biochemistry · doi:10.1146/annurev.biochem.54.1.171 · Cited by 44 · see citing works
Bartel, D. P., & Unrau, P. J. (1999) · Trends in Biochemical Sciences · doi:10.1016/s0968-0004(99)01483-8 · Cited by 44 · see citing works
Self-citationA Promiscuous Ribozyme Promotes Nucleotide Synthesis in Addition to Ribose Chemistry
Lau, M. W. L., & Unrau, P. J. (2009) · Chemistry & Biology · doi:10.1016/j.chembiol.2009.07.005 · Cited by 42 · see citing works
Self-citationAn oxocarbenium-ion intermediate of a ribozyme reaction indicated by kinetic isotope effects
Unrau, P. J., & Bartel, D. P. (2003) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.2433147100 · Cited by 37 · see citing works
Self-citationHagen, M. E., Tiley, L. S., Chung, T. D. Y., et al. (1995) · Journal of General Virology · doi:10.1099/0022-1317-76-3-603 · Cited by 36 · see citing works
Synthesis of Adenine from HCN Tetramer and Ammonium Formate
Hill, A. R., & Orgel, L. E. (2002) · Origins of Life and Evolution of Biospheres · doi:10.1023/a:1016070723772 · Cited by 36 · see citing works
Hayden, E. J., von Kiedrowski, G., & Lehman, N. (2008) · Angewandte Chemie · doi:10.1002/ange.200802177 · Cited by 30 · see citing works
Back-priming mode of ϕ6 RNA-dependent RNA polymerase
Laurila, M. R. L., Salgado, P. S., Stuart, D. I., Grimes, J. M., & Bamford, D. H. (2005) · Journal of General Virology · doi:10.1099/vir.0.80492-0 · Cited by 26 · see citing works
An efficient prebiotic synthesis of cytosine and uracil
Robertson, M. P., & Miller, S. L. (1995) · Nature · doi:10.1038/377257a0 · Cited by 25 · see citing works
Two independently selected capping ribozymes share similar substrate requirements
Zaher, H. S., Watkins, R. A., & Unrau, P. J. (2006) · RNA · doi:10.1261/rna.131306 · Cited by 21 · see citing works
Self-citation5 Re-creating an RNA Replicase
Bartel, D. P. (1999) · doi:10.1101/087969589.37.143 · Cited by 6 · see citing works
Structural Basis for the Transition from Initiation to Elongation Transcription in T7 RNA Polymerase
Yin, Y. W., & Steitz, T. A. (2020) · WORLD SCIENTIFIC eBooks · doi:10.1142/9789811215865_0039 · Cited by 6 · see citing works
A ligase ribozyme obtained from a structured pool
Yoshioka, W. (2004) · Nucleic Acids Symposium Series · doi:10.1093/nass/48.1.209 · Cited by 1 · see citing works
Flagged first, then by citations
Research works printed but not linked: 2
- [33]33. Joyce GF, Orgel LE. 2006. Progress towards understanding the origin of the RNA world. In RNA World, 3rd ed. Cold Spring Harber Laboratory Press, Cold Spring Harber, NY.
- [66]66. Soll D, Nishimura S, Moore PB. 2001. RNA. Pergamon Press.
Cited by
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Bansho, Y., Furubayashi, T., Ichihashi, N., & Yomo, T. (2016) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1524404113 · Cited by 87 · see citing works
Rethinking quasispecies theory: from fittest type to cooperative consortia
Villarreal, L. P., & Witzany, G. (2013) · World Journal of Biological Chemistry · doi:10.4331/wjbc.v4.i4.79 · Cited by 49 · see citing works
Ivica, N. A., Obermayer, B., Campbell, G. W., Rajamani, S., Gerland, U., & Chen, I. A. (2013) · Journal of Molecular Evolution · doi:10.1007/s00239-013-9584-x · Cited by 42 · see citing works
Kunnev, D., & Gospodinov, A. (2018) · Life · doi:10.3390/life8040044 · Cited by 24 · see citing works
Polymerase ribozyme efficiency increased by G/T-rich DNA oligonucleotides
Yao, C., & Müller, U. F. (2011) · RNA · doi:10.1261/rna.2726811 · Cited by 8 · see citing works
Thermodynamic Basis for the Emergence of Genomes during Prebiotic Evolution
Woo, H.-J., Vijaya Satya, R., & Reifman, J. (2012) · PLoS Computational Biology · doi:10.1371/journal.pcbi.1002534 · Cited by 6 · see citing works
“One of the simplest and most promising is the RNA world hypothesis [1,6,7], which proposes RNA molecules as precursors to modern life forms consisting of DNAs as carriers of genomes and proteins as molecular machines.”
Background
- Authors
- Cheng, L. K. L., & Unrau, P. J.
- Affiliations
- Simon Fraser University (CA)
- Venue
- Cold Spring Harbor Perspectives in Biology
- Publisher
- Cold Spring Harbor Laboratory
- Published
- 2010-06-16
- Volume
- 2
- Issue
- 10
- Pages
- a002204-a002204
- ISSN
- 1943-0264 (ISSN-L)
- PMC
- PMC2944364
- OpenAlex
- W2104294761
- Cited by
- 58
- References
- 86
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 1 · 2023: 1 · 2022: 5 · 2021: 7 · 2020: 4 · 2019: 3 · 2018: 2 · 2017: 2 · 2016: 3 · 2015: 7 · 2014: 3 · 2013: 4 · 2012: 6
- Type
- posted content
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Cold Spring Harbor Perspectives in Biology (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Origins and Evolution of Life
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › RNA and protein synthesis mechanisms
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Evolution and Genetic Dynamics
- Keywords
- origin of life, ribozymes, RNA polymerization, nucleotide synthesis, self-replicating systems, error-prone replication, RNA catalysis
- MeSH terms
- Origin of Life, Polynucleotide Ligases, RNA, DNA-Directed RNA Polymerases, RNA, Catalytic, Evolution, Molecular
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