1
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Su CI, Chuang ZS, Shie CT, Wang HI, Kao YT, Yu CY. A cis-acting ligase ribozyme generates circular RNA in vitro for ectopic protein functioning. Nat Commun 2024; 15:6607. [PMID: 39098891 PMCID: PMC11298514 DOI: 10.1038/s41467-024-51044-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 07/25/2024] [Indexed: 08/06/2024] Open
Abstract
Delivering synthetic protein-coding RNA bypassing the DNA stage for ectopic protein functioning is a novel therapeutic strategy. Joining the linear RNA head-to-tail covalently could be a state-of-the-art strategy for functioning longer. Here we enroll a cis-acting ligase ribozyme (RzL) to generate circular RNA (circRNA) in vitro for ectopic protein expression. The RNA circularization is confirmed by masking the 5' phosphate group, resisting exonuclease RNase R digestion, failing for further tailing, and sequencing the RT-PCR products of the joined region. Interestingly, one internal ribosome entry site (IRES) renders circRNA translation competent, but two IRES in cis, not trans, hamper the translation. The circRNA with highly potent in translation is conferred for antiviral functioning. Accompanying specific guided RNA, a circRNA expressing ribonuclease Cas13 shows excellent potential against the corresponding RNA virus, further extending circRNA functioning in its growing list of applications.
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Affiliation(s)
- Chan-I Su
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Zih-Shiuan Chuang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan
- National Infectious Diseases Bank, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Chi-Ting Shie
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Hsin-I Wang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Yu-Ting Kao
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Chia-Yi Yu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, 350, Taiwan.
- National Infectious Diseases Bank, National Health Research Institutes, Miaoli, 350, Taiwan.
- Department of Microbiology and Immunology, National Cheng Kung University, Tainan, 701, Taiwan.
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2
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Shechner DM. Architecture of an RNA polymerase ribozyme illuminates the RNA World. Trends Genet 2024; 40:291-292. [PMID: 38485607 PMCID: PMC11003837 DOI: 10.1016/j.tig.2024.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 02/29/2024] [Indexed: 04/11/2024]
Abstract
'Ribo-organisms' of the primordial RNA World would have needed ribozymes that catalyze RNA replication. McRae, Wan, Kristoffersen et al. recently revealed how these RNA replicases might have functioned by solving the structure of an artificial polymerase ribozyme. This work illustrates how complex RNA structures evolve, with implications for the origins of life.
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Affiliation(s)
- David M Shechner
- Department of Pharmacology, University of Washington, Seattle, WA, USA; Institute for Stem Cell and Regenerative Medicine, Seattle, WA, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.
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3
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Papastavrou N, Horning DP, Joyce GF. RNA-catalyzed evolution of catalytic RNA. Proc Natl Acad Sci U S A 2024; 121:e2321592121. [PMID: 38437533 PMCID: PMC10945747 DOI: 10.1073/pnas.2321592121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/25/2024] [Indexed: 03/06/2024] Open
Abstract
An RNA polymerase ribozyme that was obtained by directed evolution can propagate a functional RNA through repeated rounds of replication and selection, thereby enabling Darwinian evolution. Earlier versions of the polymerase did not have sufficient copying fidelity to propagate functional information, but a new variant with improved fidelity can replicate the hammerhead ribozyme through reciprocal synthesis of both the hammerhead and its complement, with the products then being selected for RNA-cleavage activity. Two evolutionary lineages were carried out in parallel, using either the prior low-fidelity or the newer high-fidelity polymerase. The former lineage quickly lost hammerhead functionality as the population diverged toward random sequences, whereas the latter evolved new hammerhead variants with improved fitness compared to the starting RNA. The increase in fitness was attributable to specific mutations that improved the replicability of the hammerhead, counterbalanced by a small decrease in hammerhead activity. Deep sequencing analysis was used to follow the course of evolution, revealing the emergence of a succession of variants that progressively diverged from the starting hammerhead as fitness increased. This study demonstrates the critical importance of replication fidelity for maintaining heritable information in an RNA-based evolving system, such as is thought to have existed during the early history of life on Earth. Attempts to recreate RNA-based life in the laboratory must achieve further improvements in replication fidelity to enable the fully autonomous Darwinian evolution of RNA enzymes as complex as the polymerase itself.
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4
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Borsley S, Gallagher JM, Leigh DA, Roberts BMW. Ratcheting synthesis. Nat Rev Chem 2024; 8:8-29. [PMID: 38102412 DOI: 10.1038/s41570-023-00558-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2023] [Indexed: 12/17/2023]
Abstract
Synthetic chemistry has traditionally relied on reactions between reactants of high chemical potential and transformations that proceed energetically downhill to either a global or local minimum (thermodynamic or kinetic control). Catalysts can be used to manipulate kinetic control, lowering activation energies to influence reaction outcomes. However, such chemistry is still constrained by the shape of one-dimensional reaction coordinates. Coupling synthesis to an orthogonal energy input can allow ratcheting of chemical reaction outcomes, reminiscent of the ways that molecular machines ratchet random thermal motion to bias conformational dynamics. This fundamentally distinct approach to synthesis allows multi-dimensional potential energy surfaces to be navigated, enabling reaction outcomes that cannot be achieved under conventional kinetic or thermodynamic control. In this Review, we discuss how ratcheted synthesis is ubiquitous throughout biology and consider how chemists might harness ratchet mechanisms to accelerate catalysis, drive chemical reactions uphill and programme complex reaction sequences.
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Affiliation(s)
- Stefan Borsley
- Department of Chemistry, University of Manchester, Manchester, UK
| | | | - David A Leigh
- Department of Chemistry, University of Manchester, Manchester, UK.
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5
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Ueda K, Mizuuchi R, Ichihashi N. Emergence of linkage between cooperative RNA replicators encoding replication and metabolic enzymes through experimental evolution. PLoS Genet 2023; 19:e1010471. [PMID: 37540715 PMCID: PMC10431678 DOI: 10.1371/journal.pgen.1010471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 08/16/2023] [Accepted: 07/18/2023] [Indexed: 08/06/2023] Open
Abstract
The integration of individually replicating genes into a primitive chromosome is a key evolutionary transition in the development of life, allowing the simultaneous inheritance of genes. However, how this transition occurred is unclear because the extended size of primitive chromosomes replicate slower than unlinked genes. Theoretical studies have suggested that a primitive chromosome can evolve in the presence of cell-like compartments, as the physical linkage prevents the stochastic loss of essential genes upon division, but experimental support for this is lacking. Here, we demonstrate the evolution of a chromosome-like RNA from two cooperative RNA replicators encoding replication and metabolic enzymes. Through their long-term replication in cell-like compartments, linked RNAs emerged with the two cooperative RNAs connected end-to-end. The linked RNAs had different mutation patterns than the two unlinked RNAs, suggesting that they were maintained as partially distinct lineages in the population. Our results provide experimental evidence supporting the plausibility of the evolution of a primitive chromosome from unlinked gene fragments, an important step in the emergence of complex biological systems.
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Affiliation(s)
- Kensuke Ueda
- Department of Life Science, Graduate School of Arts and Science, the University of Tokyo, Meguro, Tokyo, Japan
| | - Ryo Mizuuchi
- Department of Electrical Engineering and Bioscience, Faculty of Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan
- JST, FOREST, Kawaguchi, Saitama, Japan
| | - Norikazu Ichihashi
- Department of Life Science, Graduate School of Arts and Science, the University of Tokyo, Meguro, Tokyo, Japan
- Komaba Institute for Science, the University of Tokyo, Meguro, Tokyo, Japan
- Universal Biology Institute, the University of Tokyo, Meguro, Tokyo, Japan
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6
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Kasuga M, Mutsuro-Aoki H, Ando T, Tamura K. Molecular Anatomy of the Class I Ligase Ribozyme for Elucidation of the Activity-Generating Unit. BIOLOGY 2023; 12:1012. [PMID: 37508441 PMCID: PMC10376402 DOI: 10.3390/biology12071012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
The class I ligase ribozyme consists of 121 nucleotides and shows a high catalytic rate comparable to that found in natural proteinaceous polymerases. In this study, we aimed to identify the smaller active unit of the class I ligase ribozyme comprising ~50 nucleotides, comparable to the estimated length of prebiotically synthesized RNA. Based on the three-dimensional structure of the class I ligase ribozyme, mutants were prepared and their ligation activities were analyzed. Sufficient ligation activity was maintained even when shortening to 94 nucleotides. However, because it would be difficult to approach the target of ~50 nucleotides by removing only the partial structure, the class I ligase ribozyme was then split into two molecules. The ligation activity was maintained even when splitting into two molecules of 55 and 39 nucleotides. Using a system with similar split ribozymes, we analyzed the ligation activity of mutants C30, C47, and A71, which have been previously identified as the positions that contribute to catalytic activity, and discussed the structural basis of the activity of these bases. Our findings suggest the rationale for the class I ligase ribozyme's assembling from multiple fragments that would be achievable with prebiotic synthesis.
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Affiliation(s)
- Miho Kasuga
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Hiromi Mutsuro-Aoki
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Tadashi Ando
- Department of Applied Electronics, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Koji Tamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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7
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Le Vay KK, Salibi E, Ghosh B, Tang TYD, Mutschler H. Ribozyme activity modulates the physical properties of RNA-peptide coacervates. eLife 2023; 12:e83543. [PMID: 37326308 DOI: 10.7554/elife.83543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 06/01/2023] [Indexed: 06/17/2023] Open
Abstract
Condensed coacervate phases are now understood to be important features of modern cell biology, as well as valuable protocellular models in origin-of-life studies and synthetic biology. In each of these fields, the development of model systems with varied and tuneable material properties is of great importance for replicating properties of life. Here, we develop a ligase ribozyme system capable of concatenating short RNA fragments into long chains. Our results show that the formation of coacervate microdroplets with the ligase ribozyme and poly(L-lysine) enhances ribozyme rate and yield, which in turn increases the length of the anionic polymer component of the system and imparts specific physical properties to the droplets. Droplets containing active ribozyme sequences resist growth, do not wet or spread on unpassivated surfaces, and exhibit reduced transfer of RNA between droplets when compared to controls containing inactive sequences. These altered behaviours, which stem from RNA sequence and catalytic activity, constitute a specific phenotype and potential fitness advantage, opening the door to selection and evolution experiments based on a genotype-phenotype linkage.
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Affiliation(s)
- Kristian Kyle Le Vay
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Elia Salibi
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Basusree Ghosh
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - T Y Dora Tang
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Hannes Mutschler
- Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
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8
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Kakoti A, Joyce GF. RNA Polymerase Ribozyme That Recognizes the Template-Primer Complex through Tertiary Interactions. Biochemistry 2023. [PMID: 37256719 DOI: 10.1021/acs.biochem.3c00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
RNA enzymes (ribozymes) often rely on specific base-pairing interactions to engage RNA substrates, which limits the substrate sequence generality of these enzymes. An RNA polymerase ribozyme that was previously optimized by directed evolution to operate in a more efficient and sequence-general manner can now recognize the RNA template, RNA primer, and incoming nucleoside 5'-triphosphate (NTP) entirely through tertiary interactions. As with proteinaceous polymerases, these tertiary interactions are largely agnostic to the sequence of the template, which is an essential property for the unconstrained transmission of genetic information. The polymerase ribozyme exhibits Michaelis-Menten saturation kinetics, with a catalytic rate of 0.1-1 min-1 and a Km of 0.1-1 μM. Earlier forms of the polymerase did not exhibit a saturable substrate binding site, but this property emerged over the course of directed evolution as the ribozyme underwent a structural rearrangement of its catalytic center. The optimized polymerase makes tertiary contacts with both the template and primer, including a critical interaction at the C2' position of the template nucleotide that opposes the 3'-terminal nucleotide of the primer. UV cross-linking studies paint a picture of how several portions of the ribozyme, including regions that were remodeled by directed evolution, come together to position the template, primer, and NTP within the active site for RNA polymerization.
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Affiliation(s)
- Ankana Kakoti
- The Salk Institute, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Gerald F Joyce
- The Salk Institute, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
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9
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Nomura Y, Yokobayashi Y. RNA ligase ribozymes with a small catalytic core. Sci Rep 2023; 13:8584. [PMID: 37237056 DOI: 10.1038/s41598-023-35584-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/20/2023] [Indexed: 05/28/2023] Open
Abstract
Catalytic RNAs, or ribozymes, catalyze diverse chemical reactions that could have sustained primordial life in the hypothetical RNA world. Many natural ribozymes and laboratory evolved ribozymes exhibit efficient catalysis mediated by elaborate catalytic cores within complex tertiary structures. However, such complex RNA structures and sequences are unlikely to have emerged by chance during the earliest phase of chemical evolution. Here, we explored simple and small ribozyme motifs capable of ligating two RNA fragments in a template-directed fashion (ligase ribozymes). One-round selection of small ligase ribozymes followed by deep sequencing revealed a ligase ribozyme motif comprising a three-nucleotide loop opposite to the ligation junction. The observed ligation was magnesium(II) dependent and appears to form a 2'-5' phosphodiester linkage. The fact that such a small RNA motif can function as a catalyst supports a scenario in which RNA or other primordial nucleic acids played a central role in chemical evolution of life.
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Affiliation(s)
- Yoko Nomura
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
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10
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Random and Natural Non-Coding RNA Have Similar Structural Motif Patterns but Differ in Bulge, Loop, and Bond Counts. Life (Basel) 2023; 13:life13030708. [PMID: 36983865 PMCID: PMC10054693 DOI: 10.3390/life13030708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/15/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023] Open
Abstract
An important question in evolutionary biology is whether (and in what ways) genotype–phenotype (GP) map biases can influence evolutionary trajectories. Untangling the relative roles of natural selection and biases (and other factors) in shaping phenotypes can be difficult. Because the RNA secondary structure (SS) can be analyzed in detail mathematically and computationally, is biologically relevant, and a wealth of bioinformatic data are available, it offers a good model system for studying the role of bias. For quite short RNA (length L≤126), it has recently been shown that natural and random RNA types are structurally very similar, suggesting that bias strongly constrains evolutionary dynamics. Here, we extend these results with emphasis on much larger RNA with lengths up to 3000 nucleotides. By examining both abstract shapes and structural motif frequencies (i.e., the number of helices, bonds, bulges, junctions, and loops), we find that large natural and random structures are also very similar, especially when contrasted to typical structures sampled from the spaces of all possible RNA structures. Our motif frequency study yields another result, where the frequencies of different motifs can be used in machine learning algorithms to classify random and natural RNA with high accuracy, especially for longer RNA (e.g., ROC AUC 0.86 for L = 1000). The most important motifs for classification are the number of bulges, loops, and bonds. This finding may be useful in using SS to detect candidates for functional RNA within ‘junk’ DNA regions.
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11
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Benner SA. Rethinking nucleic acids from their origins to their applications. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220027. [PMID: 36633284 PMCID: PMC9835595 DOI: 10.1098/rstb.2022.0027] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/17/2022] [Indexed: 01/13/2023] Open
Abstract
Reviewed are three decades of synthetic biology research in our laboratory that has generated alternatives to standard DNA and RNA as possible informational systems to support Darwinian evolution, and therefore life, and to understand their natural history, on Earth and throughout the cosmos. From this, we have learned that: • the core structure of nucleic acids appears to be a natural outcome of non-biological chemical processes probably in constrained, intermittently irrigated, sub-aerial aquifers on the surfaces of rocky planets like Earth and/or Mars approximately 4.36 ± 0.05 billion years ago; • however, this core is not unique. Synthetic biology has generated many different molecular systems able to support the evolution of molecular information; • these alternatives to standard DNA and RNA support biotechnology, including DNA synthesis, human diagnostics, biomedical research and medicine; • in particular, they support laboratory in vitro evolution (LIVE) with performance to generate catalysts at least 104-105 fold better than standard DNA libraries, enhancing access to receptors and catalysts on demand. Coupling nanostructures to the products of LIVE with expanded DNA offers new approaches for disease therapy; and • nevertheless, a polyelectrolyte structure and size regular building blocks are required for any informational polymer to support Darwinian evolution. These features serve as universal and agnostic biosignatures, useful for seeking life throughout the Solar System. This article is part of the theme issue 'Reactivity and mechanism in chemical and synthetic biology'.
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Affiliation(s)
- Steven A. Benner
- Foundation for Applied Molecular Evolution, 13709 Progress Boulevard no. 7, Alachua, FL 32615, USA
- Firebird Biomolecular Sciences LLC, 13709 Progress Boulevard no. 17, Alachua, FL 32615, USA
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12
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Pavlinova P, Lambert CN, Malaterre C, Nghe P. Abiogenesis through gradual evolution of autocatalysis into template-based replication. FEBS Lett 2023; 597:344-379. [PMID: 36203246 DOI: 10.1002/1873-3468.14507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/20/2022] [Accepted: 09/29/2022] [Indexed: 11/11/2022]
Abstract
How life emerged from inanimate matter is one of the most intriguing questions posed to modern science. Central to this research are experimental attempts to build systems capable of Darwinian evolution. RNA catalysts (ribozymes) are a promising avenue, in line with the RNA world hypothesis whereby RNA pre-dated DNA and proteins. Since evolution in living organisms relies on template-based replication, the identification of a ribozyme capable of replicating itself (an RNA self-replicase) has been a major objective. However, no self-replicase has been identified to date. Alternatively, autocatalytic systems involving multiple RNA species capable of ligation and recombination may enable self-reproduction. However, it remains unclear how evolution could emerge in autocatalytic systems. In this review, we examine how experimentally feasible RNA reactions catalysed by ribozymes could implement the evolutionary properties of variation, heredity and reproduction, and ultimately allow for Darwinian evolution. We propose a gradual path for the emergence of evolution, initially supported by autocatalytic systems leading to the later appearance of RNA replicases.
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Affiliation(s)
- Polina Pavlinova
- Laboratoire de Biophysique et Evolution, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, Paris, France
| | - Camille N Lambert
- Laboratoire de Biophysique et Evolution, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, Paris, France
| | - Christophe Malaterre
- Laboratory of Philosophy of Science (LAPS) and Centre Interuniversitaire de Recherche sur la Science et la Technologie (CIRST), Université du Québec à Montréal (UQAM), Canada
| | - Philippe Nghe
- Laboratoire de Biophysique et Evolution, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, Paris, France
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13
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In vitro evolution of ribonucleases from expanded genetic alphabets. Proc Natl Acad Sci U S A 2022; 119:e2208261119. [PMID: 36279447 PMCID: PMC9636917 DOI: 10.1073/pnas.2208261119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability of nucleic acids to catalyze reactions (as well as store and transmit information) is important for both basic and applied science, the first in the context of molecular evolution and the origin of life and the second for biomedical applications. However, the catalytic power of standard nucleic acids (NAs) assembled from just four nucleotide building blocks is limited when compared with that of proteins. Here, we assess the evolutionary potential of libraries of nucleic acids with six nucleotide building blocks as reservoirs for catalysis. We compare the outcomes of in vitro selection experiments toward RNA-cleavage activity of two nucleic acid libraries: one built from the standard four independently replicable nucleotides and the other from six, with the two added nucleotides coming from an artificially expanded genetic information system (AEGIS). Results from comparative experiments suggest that DNA libraries with increased chemical diversity, higher information density, and larger searchable sequence spaces are one order of magnitude richer reservoirs of molecules that catalyze the cleavage of a phosphodiester bond in RNA than DNA libraries built from a standard four-nucleotide alphabet. Evolved AEGISzymes with nitro-carrying nucleobase Z appear to exploit a general acid–base catalytic mechanism to cleave that bond, analogous to the mechanism of the ribonuclease A family of protein enzymes and heavily modified DNAzymes. The AEGISzyme described here represents a new type of catalysts evolved from libraries built from expanded genetic alphabets.
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14
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Acquisition of Dual Ribozyme-Functions in Nonfunctional Short Hairpin RNAs through Kissing-Loop Interactions. LIFE (BASEL, SWITZERLAND) 2022; 12:life12101561. [PMID: 36294996 PMCID: PMC9604999 DOI: 10.3390/life12101561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/30/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
The acquisition of functions via the elongation of nucleotides is an important factor in the development of the RNA world. In our previous study, we found that the introduction of complementary seven-membered kissing loops into inactive R3C ligase ribozymes revived their ligation activity. In this study, we applied the kissing complex formation-induced rearrangement of RNAs to two nonfunctional RNAs by introducing complementary seven-membered loops into each of them. By combining these two forms of RNAs, the ligase activity (derived from the R3C ligase ribozyme) as well as cleavage activity (derived from the hammerhead ribozyme) was obtained. Thus, effective RNA evolution toward the formation of a life system may require the achievement of “multiple” functions via kissing-loop interactions, as indicated in this study. Our results point toward the versatility of kissing-loop interactions in the evolution of RNA, i.e., two small nonfunctional RNAs can gain dual functions via a kissing-loop interaction.
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15
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Stano P. A four-track perspective for bottom-up synthetic cells. Front Bioeng Biotechnol 2022; 10:1029446. [PMID: 36246382 PMCID: PMC9563707 DOI: 10.3389/fbioe.2022.1029446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022] Open
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16
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Rotrattanadumrong R, Yokobayashi Y. Experimental exploration of a ribozyme neutral network using evolutionary algorithm and deep learning. Nat Commun 2022; 13:4847. [PMID: 35977956 PMCID: PMC9385714 DOI: 10.1038/s41467-022-32538-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022] Open
Abstract
A neutral network connects all genotypes with equivalent phenotypes in a fitness landscape and plays an important role in the mutational robustness and evolvability of biomolecules. In contrast to earlier theoretical works, evidence of large neutral networks has been lacking in recent experimental studies of fitness landscapes. This suggests that evolution could be constrained globally. Here, we demonstrate that a deep learning-guided evolutionary algorithm can efficiently identify neutral genotypes within the sequence space of an RNA ligase ribozyme. Furthermore, we measure the activities of all 216 variants connecting two active ribozymes that differ by 16 mutations and analyze mutational interactions (epistasis) up to the 16th order. We discover an extensive network of neutral paths linking the two genotypes and reveal that these paths might be predicted using only information from lower-order interactions. Our experimental evaluation of over 120,000 ribozyme sequences provides important empirical evidence that neutral networks can increase the accessibility and predictability of the fitness landscape. Neutral networks, which are sets of genotypes connected via single mutations that share the same phenotype, are important for evolvability. Here, the authors provide experimental evidence of a neutral network in an RNA enzyme using a high-throughput assay and deep learning.
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Affiliation(s)
- Rachapun Rotrattanadumrong
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 9040495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 9040495, Japan.
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17
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Profiling demethylase activity using epigenetically inactivated DNAzyme. Biosens Bioelectron 2022; 207:114186. [DOI: 10.1016/j.bios.2022.114186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/28/2022] [Accepted: 03/11/2022] [Indexed: 11/02/2022]
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18
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Krochmal D, Shao Y, Li NS, DasGupta S, Shelke SA, Koirala D, Piccirilli JA. Structural basis for substrate binding and catalysis by a self-alkylating ribozyme. Nat Chem Biol 2022; 18:376-384. [PMID: 35058645 DOI: 10.1038/s41589-021-00950-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 11/23/2021] [Indexed: 12/26/2022]
Abstract
Ribozymes that react with small-molecule probes have important applications in transcriptomics and chemical biology, such as RNA labeling and imaging. Understanding the structural basis for these RNA-modifying reactions will enable the development of better tools for studying RNA. Nevertheless, high-resolution structures and underlying catalytic mechanisms for members of this ribozyme class remain elusive. Here, we focus on a self-alkylating ribozyme that catalyzes nitrogen-carbon bond formation between a specific guanine and a 2,3-disubstituted epoxide substrate and report the crystal structures of a self-alkylating ribozyme, including both alkylated and apo forms, at 1.71-Å and 2.49-Å resolution, respectively. The ribozyme assumes an elongated hairpin-like architecture preorganized to accommodate the epoxide substrate in a hook-shaped conformation. Observed reactivity of substrate analogs together with an inverse, log-linear pH dependence of the reaction rate suggests a requirement for epoxide protonation, possibly assisted by the ether oxygens within the substrate.
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Affiliation(s)
- Daniel Krochmal
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Yaming Shao
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Nan-Sheng Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Saurja DasGupta
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Sandip A Shelke
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Deepak Koirala
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Joseph A Piccirilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
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19
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Pairing statistics and melting of random DNA oligomers: Finding your partner in superdiverse environments. PLoS Comput Biol 2022; 18:e1010051. [PMID: 35404933 PMCID: PMC9022813 DOI: 10.1371/journal.pcbi.1010051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/21/2022] [Accepted: 03/22/2022] [Indexed: 11/19/2022] Open
Abstract
Understanding of the pairing statistics in solutions populated by a large number of distinct solute species with mutual interactions is a challenging topic, relevant in modeling the complexity of real biological systems. Here we describe, both experimentally and theoretically, the formation of duplexes in a solution of random-sequence DNA (rsDNA) oligomers of length L = 8, 12, 20 nucleotides. rsDNA solutions are formed by 4L distinct molecular species, leading to a variety of pairing motifs that depend on sequence complementarity and range from strongly bound, fully paired defectless helices to weakly interacting mismatched duplexes. Experiments and theory coherently combine revealing a hybridization statistics characterized by a prevalence of partially defected duplexes, with a distribution of type and number of pairing errors that depends on temperature. We find that despite the enormous multitude of inter-strand interactions, defectless duplexes are formed, involving a fraction up to 15% of the rsDNA chains at the lowest temperatures. Experiments and theory are limited here to equilibrium conditions. Several biological processes require that specific partner molecules succeed in binding after negotiating their way through a huge number of interactions with other molecules. How such molecular recognition emerges among millions distinct molecular species is an open problem. We have studied, both experimentally and theoretically, such process of “molecular recognition” in pools of highly diverse random DNA oligomers, which binds preferentially, but not exclusively, to its perfect complementary sequence. We find a complex behavior, in which some perfect pairing takes place with a non-trivial temperature dependence that we understand thorough statistical mechanics modelling. The pairing pattern of short random DNA is relevant in the context of the origin of life since the so-called “RNA World” was most probably based on the mutual recognition of random chains.
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20
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Jia TZ, Nishikawa S, Fujishima K. Sequencing the Origins of Life. BBA ADVANCES 2022; 2:100049. [PMID: 37082609 PMCID: PMC10074849 DOI: 10.1016/j.bbadva.2022.100049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/27/2022] [Accepted: 03/02/2022] [Indexed: 01/10/2023] Open
Abstract
One goal of origins of life research is to understand how primitive informational and catalytic biopolymers emerged and evolved. Recently, a number of sequencing techniques have been applied to analysis of replicating and evolving primitive biopolymer systems, providing a sequence-specific and high-resolution view of primitive chemical processes. Here, we review application of sequencing techniques to analysis of synthetic and primitive nucleic acids and polypeptides. This includes next-generation sequencing of primitive polymerization and evolution processes, followed by discussion of other novel biochemical techniques that could contribute to sequence analysis of primitive biopolymer driven chemical systems. Further application of sequencing to origins of life research, perhaps as a life detection technology, could provide insight into the origin and evolution of informational and catalytic biopolymers on early Earth or elsewhere.
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Affiliation(s)
- Tony Z. Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- Blue Marble Space Institute of Science, 600 1st Ave, Floor 1, Seattle, WA 98104, USA
- Corresponding author
| | - Shota Nishikawa
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8501, Japan
| | - Kosuke Fujishima
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa-shi, Kanagawa 252-0882, Japan
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21
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Knezic B, Keyhani-Goldau S, Schwalbe H. Mapping the conformational landscape of the neutral network of RNA sequences that connect two functional distinctly different ribozymes. Chembiochem 2022; 23:e202200022. [PMID: 35112772 PMCID: PMC9305247 DOI: 10.1002/cbic.202200022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/02/2022] [Indexed: 11/08/2022]
Abstract
During evolution of an RNA world, the development of enzymatic function was essential. Such enzymatic function was linked to RNA sequences capable of adopting specific RNA folds that possess catalytic pockets to promote catalysis. Within this primordial RNA world, initially evolved self-replicating ribozymes presumably mutated to ribozymes with new functions. In 2000, Schultes and Bartel investigated such conversion from one ribozyme to a new ribozyme with distinctly different catalytic functions. Within a neutral network that linked these two prototype ribozymes, a single RNA chain could be identified that exhibited both enzymatic functions. This system serves as a paradigm for an evolutionary system that allows neutral drifts by stepwise mutation from one ribozyme into a different ribozyme without loss of intermittent function. Here, we investigated this complex functional diversification by analyzing several RNA sequences within this neutral network between two ribozymes with class III ligase activity and with self-cleavage reactivity. We utilized rapid RNA sample preparation for NMR spectroscopic studies together with SHAPE analysis and in-line probing to characterize secondary structure changes within the neutral network. Our investigations allowed delineation of the 2 nd structure space and by comparison with the previously determined catalytic function allowed correlation of the structure-function relation of ribozyme function in this neutral network.
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Affiliation(s)
- Bozana Knezic
- Goethe-Universitat Frankfurt am Main, Biochemistry, Chemistry, and Pharmacy, GERMANY
| | - Sara Keyhani-Goldau
- Goethe-Universitat Frankfurt am Main, Biochemistry, Chemistry, and Pharmacy, GERMANY
| | - Harald Schwalbe
- Goethe-Universitat Frankfurt am Main, Institut für Organische Chemie und Chemische Biologie, Max-von-Laue-Str. 7, 60438, Frankfurt, GERMANY
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22
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Spirov AV, Myasnikova EM. Heuristic algorithms in evolutionary computation and modular organization of biological macromolecules: Applications to in vitro evolution. PLoS One 2022; 17:e0260497. [PMID: 35085255 PMCID: PMC8794168 DOI: 10.1371/journal.pone.0260497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/10/2021] [Indexed: 11/19/2022] Open
Abstract
Evolutionary computing (EC) is an area of computer sciences and applied mathematics covering heuristic optimization algorithms inspired by evolution in Nature. EC extensively study all the variety of methods which were originally based on the principles of selectionism. As a result, many new algorithms and approaches, significantly more efficient than classical selectionist schemes, were found. This is especially true for some families of special problems. There are strong arguments to believe that EC approaches are quite suitable for modeling and numerical analysis of those methods of synthetic biology and biotechnology that are known as in vitro evolution. Therefore, it is natural to expect that the new algorithms and approaches developed in EC can be effectively applied in experiments on the directed evolution of biological macromolecules. According to the John Holland's Schema theorem, the effective evolutionary search in genetic algorithms (GA) is provided by identifying short schemata of high fitness which in the further search recombine into the larger building blocks (BBs) with higher and higher fitness. The multimodularity of functional biological macromolecules and the preservation of already found modules in the evolutionary search have a clear analogy with the BBs in EC. It seems reasonable to try to transfer and introduce the methods of EC, preserving BBs and essentially accelerating the search, into experiments on in vitro evolution. We extend the key instrument of the Holland's theory, the Royal Roads fitness function, to problems of the in vitro evolution (Biological Royal Staircase, BioRS, functions). The specific version of BioRS developed in this publication arises from the realities of experimental evolutionary search for (DNA-) RNA-devices (aptazymes). Our numerical tests showed that for problems with the BioRS functions, simple heuristic algorithms, which turned out to be very effective for preserving BBs in GA, can be very effective in in vitro evolution approaches. We are convinced that such algorithms can be implemented in modern methods of in vitro evolution to achieve significant savings in time and resources and a significant increase in the efficiency of evolutionary search.
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Affiliation(s)
- Alexander V. Spirov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry Russian Academy of Sciences, St. Petersburg, Russia
- The Institute of Scientific Information for Social Sciences RAS, Moscow, Russia
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23
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Czerniak T, Saenz JP. Lipid membranes modulate the activity of RNA through sequence-dependent interactions. Proc Natl Acad Sci U S A 2022; 119:e2119235119. [PMID: 35042820 PMCID: PMC8794826 DOI: 10.1073/pnas.2119235119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/02/2021] [Indexed: 12/11/2022] Open
Abstract
RNA is a ubiquitous biomolecule that can serve as both catalyst and information carrier. Understanding how RNA bioactivity is controlled is crucial for elucidating its physiological roles and potential applications in synthetic biology. Here, we show that lipid membranes can act as RNA organization platforms, introducing a mechanism for riboregulation. The activity of R3C ribozyme can be modified by the presence of lipid membranes, with direct RNA-lipid interactions dependent on RNA nucleotide content, base pairing, and length. In particular, the presence of guanine in short RNAs is crucial for RNA-lipid interactions, and G-quadruplex formation further promotes lipid binding. Lastly, by artificially modifying the R3C substrate sequence to enhance membrane binding, we generated a lipid-sensitive ribozyme reaction with riboswitch-like behavior. These findings introduce RNA-lipid interactions as a tool for developing synthetic riboswitches and RNA-based lipid biosensors and bear significant implications for RNA world scenarios for the origin of life.
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Affiliation(s)
- Tomasz Czerniak
- B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, 01307 Dresden, Germany
| | - James P Saenz
- B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, 01307 Dresden, Germany
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24
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Depmeier H, Hoffmann E, Bornewasser L, Kath‐Schorr S. Strategies for Covalent Labeling of Long RNAs. Chembiochem 2021; 22:2826-2847. [PMID: 34043861 PMCID: PMC8518768 DOI: 10.1002/cbic.202100161] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 05/26/2021] [Indexed: 12/17/2022]
Abstract
The introduction of chemical modifications into long RNA molecules at specific positions for visualization, biophysical investigations, diagnostic and therapeutic applications still remains challenging. In this review, we present recent approaches for covalent internal labeling of long RNAs. Topics included are the assembly of large modified RNAs via enzymatic ligation of short synthetic oligonucleotides and synthetic biology approaches preparing site-specifically modified RNAs via in vitro transcription using an expanded genetic alphabet. Moreover, recent approaches to employ deoxyribozymes (DNAzymes) and ribozymes for RNA labeling and RNA methyltransferase based labeling strategies are presented. We discuss the potentials and limits of the individual methods, their applicability for RNAs with several hundred to thousands of nucleotides in length and indicate future directions in the field.
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Affiliation(s)
- Hannah Depmeier
- University of CologneDepartment of ChemistryGreinstr. 450939CologneGermany
| | - Eva Hoffmann
- University of CologneDepartment of ChemistryGreinstr. 450939CologneGermany
| | - Lisa Bornewasser
- University of CologneDepartment of ChemistryGreinstr. 450939CologneGermany
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25
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Portillo X, Huang YT, Breaker RR, Horning DP, Joyce GF. Witnessing the structural evolution of an RNA enzyme. eLife 2021; 10:71557. [PMID: 34498588 PMCID: PMC8460264 DOI: 10.7554/elife.71557] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
An RNA polymerase ribozyme that has been the subject of extensive directed evolution efforts has attained the ability to synthesize complex functional RNAs, including a full-length copy of its own evolutionary ancestor. During the course of evolution, the catalytic core of the ribozyme has undergone a major structural rearrangement, resulting in a novel tertiary structural element that lies in close proximity to the active site. Through a combination of site-directed mutagenesis, structural probing, and deep sequencing analysis, the trajectory of evolution was seen to involve the progressive stabilization of the new structure, which provides the basis for improved catalytic activity of the ribozyme. Multiple paths to the new structure were explored by the evolving population, converging upon a common solution. Tertiary structural remodeling of RNA is known to occur in nature, as evidenced by the phylogenetic analysis of extant organisms, but this type of structural innovation had not previously been observed in an experimental setting. Despite prior speculation that the catalytic core of the ribozyme had become trapped in a narrow local fitness optimum, the evolving population has broken through to a new fitness locale, raising the possibility that further improvement of polymerase activity may be achievable.
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Affiliation(s)
- Xavier Portillo
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
| | | | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States.,Howard Hughes Medical Institute, New Haven, United States
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26
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Structured sequences emerge from random pool when replicated by templated ligation. Proc Natl Acad Sci U S A 2021; 118:2018830118. [PMID: 33593911 PMCID: PMC7923349 DOI: 10.1073/pnas.2018830118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The structure of life emerged from randomness. This is attributed to selection by molecular Darwinian evolution. This study found that random templated ligation led to the simultaneous elongation and sequence selection of oligomers. Product strands showed highly structured sequence motifs which inhibited self-folding and built self-templating reaction networks. By the reduction of the sequence space, the kinetics of duplex formation increased and led to a faster replication through the ligation process. These findings imply that elementary binding properties of nucleotides can lead to an early selection of sequences even before the onset of Darwinian evolution. This suggests that such a simplification of sequence space could result in faster downstream selection for sequence-based function for the origin of life. The central question in the origin of life is to understand how structure can emerge from randomness. The Eigen theory of replication states, for sequences that are copied one base at a time, that the replication fidelity has to surpass an error threshold to avoid that replicated specific sequences become random because of the incorporated replication errors [M. Eigen, Naturwissenschaften 58 (10), 465–523 (1971)]. Here, we showed that linking short oligomers from a random sequence pool in a templated ligation reaction reduced the sequence space of product strands. We started from 12-mer oligonucleotides with two bases in all possible combinations and triggered enzymatic ligation under temperature cycles. Surprisingly, we found the robust creation of long, highly structured sequences with low entropy. At the ligation site, complementary and alternating sequence patterns developed. However, between the ligation sites, we found either an A-rich or a T-rich sequence within a single oligonucleotide. Our modeling suggests that avoidance of hairpins was the likely cause for these two complementary sequence pools. What emerged was a network of complementary sequences that acted both as templates and substrates of the reaction. This self-selecting ligation reaction could be restarted by only a few majority sequences. The findings showed that replication by random templated ligation from a random sequence input will lead to a highly structured, long, and nonrandom sequence pool. This is a favorable starting point for a subsequent Darwinian evolution searching for higher catalytic functions in an RNA world scenario.
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27
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Wang Y, Wang Y, Song D, Sun X, Zhang Z, Li X, Li Z, Yu H. A Threose Nucleic Acid Enzyme with RNA Ligase Activity. J Am Chem Soc 2021; 143:8154-8163. [PMID: 34028252 DOI: 10.1021/jacs.1c02895] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Threose nucleic acid (TNA) has been considered a potential RNA progenitor in evolution due to its chemical simplicity and base pairing property. Catalytic TNA sequences with RNA ligase activities might have facilitated the transition to the RNA world. Here we report the isolation of RNA ligase TNA enzymes by in vitro selection. The identified TNA enzyme T8-6 catalyzes the formation of a 2'-5' phosphoester bond between a 2',3'-diol and a 5'-triphosphate group, with a kobs of 1.1 × 10-2 min-1 (40 mM Mg2+, pH 9.0). For efficient reaction, T8-6 requires UA|GA at the ligation junction and tolerates variations at other substrate positions. Functional RNAs such as hammerhead ribozyme can be prepared by T8-6-catalyzed ligation, with site-specific introduction of a 2'-5' linkage. Together, this work provides experimental support for TNA as a plausible pre-RNA genetic polymer and also offers an alternative molecular tool for biotechnology.
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Affiliation(s)
- Yao Wang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu 210023, China
| | - Yueyao Wang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu 210023, China.,Applied Adaptome Immunology Institute, Jiangsu Industrial Technology Research Institute, Nanjing, Jiangsu 210023, China
| | - Dongfan Song
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xin Sun
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu 210023, China
| | - Ze Zhang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xintong Li
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Zhe Li
- State Key Laboratory of Analytical Chemistry for Life Science, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Hanyang Yu
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu 210023, China
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28
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Chizzolini F, Kent AD, Passalacqua LFM, Lupták A. Enzymatic RNA Production from NTPs Synthesized from Nucleosides and Trimetaphosphate*. Chembiochem 2021; 22:2098-2101. [PMID: 33798271 DOI: 10.1002/cbic.202100085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/29/2021] [Indexed: 01/22/2023]
Abstract
A mechanism of nucleoside triphosphorylation would have been critical in an evolving "RNA world" to provide high-energy substrates for reactions such as RNA polymerization. However, synthetic approaches to produce ribonucleoside triphosphates (rNTPs) have suffered from conditions such as high temperatures or high pH that lead to increased RNA degradation, as well as substrate production that cannot sustain replication. Previous reports have demonstrated that cyclic trimetaphosphate (cTmp) can react with nucleosides to form rNTPs under prebiotically-relevant conditions, but their reaction rates were unknown and the influence of reaction conditions not well-characterized. Here we established a sensitive assay that allowed for the determination of second-order rate constants for all four rNTPs, ranging from 1.7×10-6 to 6.5×10-6 M-1 s-1 . The ATP reaction shows a linear dependence on pH and Mg2+ , and an enthalpy of activation of 88±4 kJ/mol. At millimolar nucleoside and cTmp concentrations, the rNTP production rate is sufficient to facilitate RNA synthesis by both T7 RNA polymerase and a polymerase ribozyme. We suggest that the optimized reaction of cTmp with nucleosides may provide a viable connection between prebiotic nucleotide synthesis and RNA replication.
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Affiliation(s)
- Fabio Chizzolini
- Department of Pharmaceutical Sciences, University of California at Irvine, Irvine, CA, 92617, USA
| | - Alexandra D Kent
- Department of Chemistry, University of California at Irvine, Irvine, CA, 92617, USA
| | - Luiz F M Passalacqua
- Department of Pharmaceutical Sciences, University of California at Irvine, Irvine, CA, 92617, USA
| | - Andrej Lupták
- Department of Pharmaceutical Sciences, University of California at Irvine, Irvine, CA, 92617, USA.,Department of Chemistry, University of California at Irvine, Irvine, CA, 92617, USA.,Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, CA, 92617, USA
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29
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Modulation of photosynthesis and other proteins during water-stress. Mol Biol Rep 2021; 48:3681-3693. [PMID: 33856605 DOI: 10.1007/s11033-021-06329-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/31/2021] [Indexed: 10/25/2022]
Abstract
Protein changes under drought or water stress conditions have been widely investigated. These investigations have given us enormous understanding of how drought is manifested in plants and how plants respond and adopt to such conditions. Chlorophyll fluoroescence, gas exchange, OMICS, biochemical and molecular analyses have shed light on regulation of physiology and photosynthesis of plants under drought. Use of proteomics has greatly increased the repertoire of drought-associated proteins which nevertheless, need to be investigated for their mechanistic and functional roles. Roles of such proteins have been succinctly discussed in various review articles, however more information on their functional role in countering drought is needed. In this review, recent developments in the field, alterations in the abundance of plant proteins in response to drought, monitored through numerous proteomic and immuno-blot analyses, and how these could affect plants growth and development, are discussed.
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30
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Ameta S, Matsubara YJ, Chakraborty N, Krishna S, Thutupalli S. Self-Reproduction and Darwinian Evolution in Autocatalytic Chemical Reaction Systems. Life (Basel) 2021; 11:308. [PMID: 33916135 PMCID: PMC8066523 DOI: 10.3390/life11040308] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 11/18/2022] Open
Abstract
Understanding the emergence of life from (primitive) abiotic components has arguably been one of the deepest and yet one of the most elusive scientific questions. Notwithstanding the lack of a clear definition for a living system, it is widely argued that heredity (involving self-reproduction) along with compartmentalization and metabolism are key features that contrast living systems from their non-living counterparts. A minimal living system may be viewed as "a self-sustaining chemical system capable of Darwinian evolution". It has been proposed that autocatalytic sets of chemical reactions (ACSs) could serve as a mechanism to establish chemical compositional identity, heritable self-reproduction, and evolution in a minimal chemical system. Following years of theoretical work, autocatalytic chemical systems have been constructed experimentally using a wide variety of substrates, and most studies, thus far, have focused on the demonstration of chemical self-reproduction under specific conditions. While several recent experimental studies have raised the possibility of carrying out some aspects of experimental evolution using autocatalytic reaction networks, there remain many open challenges. In this review, we start by evaluating theoretical studies of ACSs specifically with a view to establish the conditions required for such chemical systems to exhibit self-reproduction and Darwinian evolution. Then, we follow with an extensive overview of experimental ACS systems and use the theoretically established conditions to critically evaluate these empirical systems for their potential to exhibit Darwinian evolution. We identify various technical and conceptual challenges limiting experimental progress and, finally, conclude with some remarks about open questions.
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Affiliation(s)
- Sandeep Ameta
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Yoshiya J. Matsubara
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Nayan Chakraborty
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Sandeep Krishna
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Shashi Thutupalli
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore 560089, India
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31
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Setterholm NA, Haratipour P, Kashemirov BA, McKenna CE, Joyce GF. Kinetic Effects of β,γ-Modified Deoxynucleoside 5'-Triphosphate Analogues on RNA-Catalyzed Polymerization of DNA. Biochemistry 2020; 60:1-5. [PMID: 33356161 DOI: 10.1021/acs.biochem.0c00779] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A recently described DNA polymerase ribozyme, obtained by in vitro evolution, provides the opportunity to investigate mechanistic features of RNA catalysis using methods that previously had only been applied to DNA polymerase proteins. Insight can be gained into the transition state of the DNA polymerization reaction by studying the behavior of various β,γ-bridging substituted methylene (CXY; X, Y = H, halo, methyl) or imido (NH) dNTP analogues that differ with regard to the pKa4 of the bisphosphonate or imidodiphosphate leaving group. The apparent rate constant (kpol) of the polymerase ribozyme was determined for analogues of dGTP and dCTP that span a broad range of acidities for the leaving group, ranging from 7.8 for the CF2-bisphosphonate to 11.6 for the CHCH3-bisphosphonate. A Brønsted plot of log(kpol) versus pKa4 of the leaving group demonstrates linear free energy relationships (LFERs) for dihalo-, monohalo-, and non-halogen-substituted analogues of the dNTPs, with negative slopes, as has been observed for DNA polymerase proteins. The unsubstituted dNTPs have a faster catalytic rate than would be predicted from consideration of the linear free energy relationship alone, presumably due to a relatively more favorable interaction of the β,γ-bridging oxygen within the active site. Although the DNA polymerase ribozyme is considerably slower than DNA polymerase proteins, it exhibits a similar LFER fingerprint, suggesting mechanistic commonality pertaining to the buildup of negative charge in the transition state, despite the very different chemical compositions of the two catalysts.
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Affiliation(s)
- Noah A Setterholm
- The Salk Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Pouya Haratipour
- Department of Chemistry, Dana and David Dornsife College of Letters, Arts, and Sciences, University of Southern California, University Park Campus, Los Angeles, California 90089, United States
| | - Boris A Kashemirov
- Department of Chemistry, Dana and David Dornsife College of Letters, Arts, and Sciences, University of Southern California, University Park Campus, Los Angeles, California 90089, United States
| | - Charles E McKenna
- Department of Chemistry, Dana and David Dornsife College of Letters, Arts, and Sciences, University of Southern California, University Park Campus, Los Angeles, California 90089, United States
| | - Gerald F Joyce
- The Salk Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
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32
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Synak J, Rybarczyk A, Blazewicz J. Multi-agent approach to sequence structure simulation in the RNA World hypothesis. PLoS One 2020; 15:e0238253. [PMID: 32857812 PMCID: PMC7455006 DOI: 10.1371/journal.pone.0238253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 08/12/2020] [Indexed: 12/03/2022] Open
Abstract
The origins of life on Earth have been the subject of inquiry since the early days of philosophical thought and are still intensively investigated by the researchers around the world. One of the theories explaining the life emergence, that gained the most attention recently is the RNA World hypothesis, which assumes that life on Earth was sparked by replicating RNA chains. Since wet lab analysis is time-consuming, many mathematical and computational approaches have been proposed that try to explain the origins of life. Recently proposed one, based on the work by Takeuchi and Hogeweg, addresses the problem of interplay between RNA replicases and RNA parasitic species, which is crucial for understanding the first steps of prebiotic evolution. In this paper, the aforementioned model has been extended and modified by introducing RNA sequence (structure) information and mutation rate close to real one. It allowed to observe the simple evolution mechanisms, which could have led to the more complicated systems and eventually, to the formation of the first cells. The main goal of this study was to determine the conditions that allowed the spontaneous emergence and evolution of the prebiotic replicases equipped with simple functional domains within a large population. Here we show that polymerase ribozymes could have appeared randomly and then quickly started to copy themselves in order for the system to reach equilibrium. It has been shown that evolutionary selection works even in the simplest systems.
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Affiliation(s)
- Jaroslaw Synak
- Institute of Computing Science, Poznan University of Technology, Poznan, Poland
- European Center for Bioinformatics and Genomics, Poznan, Poland
| | - Agnieszka Rybarczyk
- Institute of Computing Science, Poznan University of Technology, Poznan, Poland
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- European Center for Bioinformatics and Genomics, Poznan, Poland
- * E-mail: (JB); (AR)
| | - Jacek Blazewicz
- Institute of Computing Science, Poznan University of Technology, Poznan, Poland
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- European Center for Bioinformatics and Genomics, Poznan, Poland
- * E-mail: (JB); (AR)
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33
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Tjhung KF, Shokhirev MN, Horning DP, Joyce GF. An RNA polymerase ribozyme that synthesizes its own ancestor. Proc Natl Acad Sci U S A 2020; 117:2906-2913. [PMID: 31988127 PMCID: PMC7022166 DOI: 10.1073/pnas.1914282117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The RNA-based organisms from which modern life is thought to have descended would have depended on an RNA polymerase ribozyme to copy functional RNA molecules, including copying the polymerase itself. Such a polymerase must have been capable of copying structured RNAs with high efficiency and high fidelity to maintain genetic information across successive generations. Here the class I RNA polymerase ribozyme was evolved in vitro for the ability to synthesize functional ribozymes, resulting in the markedly improved ability to synthesize complex RNAs using nucleoside 5'-triphosphate (NTP) substrates. The polymerase is descended from the class I ligase, which contains the same catalytic core as the polymerase. The class I ligase can be synthesized by the improved polymerase as three separate RNA strands that assemble to form a functional ligase. The polymerase also can synthesize the complement of each of these three strands. Despite this remarkable level of activity, only a very small fraction of the assembled ligases retain catalytic activity due to the presence of disabling mutations. Thus, the fidelity of RNA polymerization should be considered a major impediment to the construction of a self-sustained, RNA-based evolving system. The propagation of heritable information requires both efficient and accurate synthesis of genetic molecules, a requirement relevant to both laboratory systems and the early history of life on Earth.
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Affiliation(s)
- Katrina F Tjhung
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute, La Jolla, CA 92037
| | - Maxim N Shokhirev
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute, La Jolla, CA 92037
| | - David P Horning
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute, La Jolla, CA 92037
| | - Gerald F Joyce
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute, La Jolla, CA 92037
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34
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Janzen E, Blanco C, Peng H, Kenchel J, Chen IA. Promiscuous Ribozymes and Their Proposed Role in Prebiotic Evolution. Chem Rev 2020; 120:4879-4897. [PMID: 32011135 PMCID: PMC7291351 DOI: 10.1021/acs.chemrev.9b00620] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
The ability of enzymes,
including ribozymes, to catalyze side reactions
is believed to be essential to the evolution of novel biochemical
activities. It has been speculated that the earliest ribozymes, whose
emergence marked the origin of life, were low in activity but high
in promiscuity, and that these early ribozymes gave rise to specialized
descendants with higher activity and specificity. Here, we review
the concepts related to promiscuity and examine several cases of highly
promiscuous ribozymes. We consider the evidence bearing on the question
of whether de novo ribozymes would be quantitatively
more promiscuous than later evolved ribozymes or protein enzymes.
We suggest that while de novo ribozymes appear to
be promiscuous in general, they are not obviously more promiscuous
than more highly evolved or active sequences. Promiscuity is a trait
whose value would depend on selective pressures, even during prebiotic
evolution.
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Affiliation(s)
- Evan Janzen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Celia Blanco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Huan Peng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Josh Kenchel
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Irene A Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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35
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Chizzolini F, Passalacqua LFM, Oumais M, Dingilian AI, Szostak JW, Lupták A. Large Phenotypic Enhancement of Structured Random RNA Pools. J Am Chem Soc 2020; 142:1941-1951. [PMID: 31887027 DOI: 10.1021/jacs.9b11396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Laboratory evolution of functional RNAs has applications in many areas of chemical and synthetic biology. In vitro selections critically depend on the presence of functional molecules, such as aptamers and ribozymes, in the starting sequence pools. For selection of novel functions the pools are typically transcribed from random-sequence DNA templates, yielding a highly diverse set of RNAs that contain a multitude of folds and biochemical activities. The phenotypic potential, the frequency of functional RNAs, is very low, requiring large complexity of starting pools, surpassing 1015 different sequences, to identify highly active isolates. Furthermore, the majority of random sequences is not structured and has a high propensity for aggregation; the in vitro selection process thus involves not just enrichment of functional RNAs, but also their purification from aggregation-prone "free-riders". We reasoned that purification of the nonaggregating, monomeric subpopulation of a random-sequence RNA pool will yield pools of folded, functional RNAs. We performed six rounds of selection for monomeric sequences and show that the enriched population is compactly folded. In vitro selections originating from various mixtures of the compact pool and a fully random pool showed that sequences from the compact pool always dominate the population once a biochemical activity is detectable. A head-to-head competition of the two pools starting from a low (5 × 1012) sequence diversity revealed that the phenotypic potential of the compact pool is about 1000-times higher than the fully random pool. A selection for folded and monomeric RNA pools thus greatly increases the frequency of functional RNAs from that seen in random-sequence pools, providing a facile experimental approach to isolation of highly active functional RNAs from low-diversity populations.
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Affiliation(s)
- Fabio Chizzolini
- Department of Pharmaceutical Sciences , University of California at Irvine , Irvine , California 92697 , United States
| | - Luiz F M Passalacqua
- Department of Pharmaceutical Sciences , University of California at Irvine , Irvine , California 92697 , United States
| | - Mona Oumais
- Department of Chemistry , University of California at Irvine , Irvine , California 92697 , United States
| | - Armine I Dingilian
- Department of Pharmaceutical Sciences , University of California at Irvine , Irvine , California 92697 , United States
| | - Jack W Szostak
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , Boston , Massachusetts 02114 , United States.,Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Andrej Lupták
- Department of Pharmaceutical Sciences , University of California at Irvine , Irvine , California 92697 , United States.,Department of Chemistry , University of California at Irvine , Irvine , California 92697 , United States.,Department of Molecular Biology and Biochemistry , University of California at Irvine , Irvine , California 92697 , United States
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36
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Nomura Y, Yokobayashi Y. Systematic minimization of RNA ligase ribozyme through large-scale design-synthesis-sequence cycles. Nucleic Acids Res 2019; 47:8950-8960. [PMID: 31504757 PMCID: PMC6755084 DOI: 10.1093/nar/gkz729] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/08/2019] [Accepted: 08/15/2019] [Indexed: 01/15/2023] Open
Abstract
Template-directed RNA ligation catalyzed by an RNA enzyme (ribozyme) is a plausible and important reaction that could have been involved in transferring genetic information during prebiotic evolution. Laboratory evolution experiments have yielded several classes of ligase ribozymes, but their minimal sequence requirements remain largely unexplored. Because selection experiments strongly favor highly active sequences, less active but smaller catalytic motifs may have been overlooked in these experiments. We used large-scale DNA synthesis and high-throughput ribozyme assay enabled by deep sequencing to systematically minimize a previously laboratory-evolved ligase ribozyme. After designing and evaluating >10 000 sequences, we identified catalytic cores as small as 18 contiguous bases that catalyze template-directed regiospecific RNA ligation. The fact that such a short sequence can catalyze this critical reaction suggests that similarly simple or even simpler motifs may populate the RNA sequence space which could have been accessible to the prebiotic ribozymes.
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Affiliation(s)
- Yoko Nomura
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
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37
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The difficult case of an RNA-only origin of life. Emerg Top Life Sci 2019; 3:469-475. [PMID: 33523163 PMCID: PMC7289000 DOI: 10.1042/etls20190024] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 11/17/2022]
Abstract
The RNA world hypothesis is probably the most extensively studied model for the emergence of life on Earth. Despite a large body of evidence supporting the idea that RNA is capable of kick-starting autocatalytic self-replication and thus initiating the emergence of life, seemingly insurmountable weaknesses in the theory have also been highlighted. These problems could be overcome by novel experimental approaches, including out-of-equilibrium environments, and the exploration of an early co-evolution of RNA and other key biomolecules such as peptides and DNA, which might be necessary to mitigate the shortcomings of RNA-only systems.
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38
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Akoopie A, Müller UF. The NTP binding site of the polymerase ribozyme. Nucleic Acids Res 2019; 46:10589-10597. [PMID: 30289487 PMCID: PMC6237761 DOI: 10.1093/nar/gky898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 10/03/2018] [Indexed: 11/15/2022] Open
Abstract
A previously developed RNA polymerase ribozyme uses nucleoside triphosphates (NTPs) to extend a primer 3′-terminus, templated by an RNA template with good fidelity, forming 3′-5′-phosphordiester bonds. Indirect evidence has suggested that the ribozyme's accessory domain binds the NTP with a highly conserved purine-rich loop. To determine the NTP binding site more precisely we evolved the ribozyme for efficient use of 6-thio guanosine triphosphate (6sGTP). 6sGTP never appeared in the evolutionary history of the ribozyme, therefore it was expected that mutations would appear at the NTP binding site, adapting to more efficient binding of 6sGTP. Indeed, the evolution identified three mutations that mediate 200-fold improved incorporation kinetics for 6sGTP. A >50-fold effect resulted from mutation A156U in the purine-rich loop, identifying the NTP binding site. This mutation acted weakly cooperative with two other beneficial mutations, C113U in the P2 stem near the catalytic site, and C79U on the surface of the catalytic domain. The preference pattern of the ribozyme for different NTPs changed when position 156 was mutated, confirming a direct contact between position 156 and the NTP. The results suggest that A156 stabilizes the NTP in the active site by a hydrogen bond to the Hoogsteen face of the NTP.
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Affiliation(s)
- Arvin Akoopie
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Ulrich F Müller
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
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39
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Bendixsen DP, Collet J, Østman B, Hayden EJ. Genotype network intersections promote evolutionary innovation. PLoS Biol 2019; 17:e3000300. [PMID: 31136568 PMCID: PMC6555535 DOI: 10.1371/journal.pbio.3000300] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 06/07/2019] [Accepted: 05/15/2019] [Indexed: 12/27/2022] Open
Abstract
Evolutionary innovations are qualitatively novel traits that emerge through evolution and increase biodiversity. The genetic mechanisms of innovation remain poorly understood. A systems view of innovation requires the analysis of genotype networks—the vast networks of genetic variants that produce the same phenotype. Innovations can occur at the intersection of two different genotype networks. However, the experimental characterization of genotype networks has been hindered by the vast number of genetic variants that need to be functionally analyzed. Here, we use high-throughput sequencing to study the fitness landscape at the intersection of the genotype networks of two catalytic RNA molecules (ribozymes). We determined the ability of numerous neighboring RNA sequences to catalyze two different chemical reactions, and we use these data as a proxy for a genotype to fitness map where two functions come in close proximity. We find extensive functional overlap, and numerous genotypes can catalyze both functions. We demonstrate through evolutionary simulations that these numerous points of intersection facilitate the discovery of a new function. However, the rate of adaptation of the new function depends upon the local ruggedness around the starting location in the genotype network. As a consequence, one direction of adaptation is more rapid than the other. We find that periods of neutral evolution increase rates of adaptation to the new function by allowing populations to spread out in their genotype network. Our study reveals the properties of a fitness landscape where genotype networks intersect and the consequences for evolutionary innovations. Our results suggest that historic innovations in natural systems may have been facilitated by overlapping genotype networks. The determination of the empirical fitness landscape at the genotypic intersection between two different catalytic RNA (ribozyme) functions reveals details about how novel traits can emerge through evolutionary innovation.
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Affiliation(s)
- Devin P. Bendixsen
- Biomolecular Sciences Graduate Programs, Boise State University, Boise, Idaho, United States of America
- * E-mail: (DPB); (EJH)
| | - James Collet
- Department of Biological Science, Boise State University, Boise, Idaho, United States of America
| | - Bjørn Østman
- Keck Graduate Institute, Claremont, California, United States of America
| | - Eric J. Hayden
- Biomolecular Sciences Graduate Programs, Boise State University, Boise, Idaho, United States of America
- Department of Biological Science, Boise State University, Boise, Idaho, United States of America
- * E-mail: (DPB); (EJH)
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40
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Li J, Liu C. Coding or Noncoding, the Converging Concepts of RNAs. Front Genet 2019; 10:496. [PMID: 31178900 PMCID: PMC6538810 DOI: 10.3389/fgene.2019.00496] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 05/06/2019] [Indexed: 12/18/2022] Open
Abstract
Technological advances over the past decade have unraveled the remarkable complexity of RNA. The identification of small peptides encoded by long non-coding RNAs (lncRNAs) as well as regulatory functions mediated by non-coding regions of mRNAs have further complicated our understanding of the multifaceted functions of RNA. In this review, we summarize current evidence pointing to dual roles of RNA molecules defined by their coding and non-coding potentials. We also discuss how the emerging roles of RNA transform our understanding of gene expression and evolution.
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Affiliation(s)
- Jing Li
- CAS Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Kunming, China
| | - Changning Liu
- CAS Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Kunming, China
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41
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Sosson M, Pfeffer D, Richert C. Enzyme-free ligation of dimers and trimers to RNA primers. Nucleic Acids Res 2019; 47:3836-3845. [PMID: 30869145 PMCID: PMC6486630 DOI: 10.1093/nar/gkz160] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 01/19/2023] Open
Abstract
The template-directed formation of phosphodiester bonds between two nucleic acid components is a pivotal process in biology. To induce such a reaction in the absence of enzymes is a challenge. This challenge has been met for the extension of a primer with mononucleotides, but the ligation of short oligonucleotides (dimers or trimers) has proven difficult. Here we report a method for ligating dimers and trimers of ribonucleotides using in situ activation in aqueous buffer. All 16 different dimers and two trimers were tested. Binding studies by NMR showed low millimolar dissociation constants for complexes between representative dimers and hairpins mimicking primer-template duplexes, confirming that a weak template effect is not the cause of the poor ligating properties of these short oligomers. Rather, cyclization was found to compete with ligation, with up to 90% of dimer being converted to the cyclic form during the course of an assay. This side reaction is strongly sequence dependent and more pronounced for dimers than for trimers. Under optimized reaction conditions, high yields were observed with strongly pairing purines at the 3'-terminus. These results show that short oligomers of ribonucleotides are competent reactants in enzyme-free copying.
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Affiliation(s)
- Marilyne Sosson
- Institute of Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Daniel Pfeffer
- Institute of Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Clemens Richert
- Institute of Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
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42
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Le Vay K, Weise LI, Libicher K, Mascarenhas J, Mutschler H. Templated Self‐Replication in Biomimetic Systems. ACTA ACUST UNITED AC 2019; 3:e1800313. [DOI: 10.1002/adbi.201800313] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/06/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Kristian Le Vay
- Biomimetic SystemsMax Planck Institute of Biochemistry Martinsried Germany
| | - Laura Isabel Weise
- Biomimetic SystemsMax Planck Institute of Biochemistry Martinsried Germany
| | - Kai Libicher
- Biomimetic SystemsMax Planck Institute of Biochemistry Martinsried Germany
| | - Judita Mascarenhas
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial Microbiology Marburg Germany
| | - Hannes Mutschler
- Biomimetic SystemsMax Planck Institute of Biochemistry Martinsried Germany
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43
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Yokobayashi Y. Applications of high-throughput sequencing to analyze and engineer ribozymes. Methods 2019; 161:41-45. [PMID: 30738128 DOI: 10.1016/j.ymeth.2019.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/04/2019] [Accepted: 02/03/2019] [Indexed: 01/22/2023] Open
Abstract
A large number of catalytic RNAs, or ribozymes, have been identified in the genomes of various organisms and viruses. Ribozymes are involved in biological processes such as regulation of gene expression and viral replication, but biological roles of many ribozymes still remain unknown. Ribozymes have also inspired researchers to engineer synthetic ribozymes that function as sensors or gene switches. To gain deeper understanding of the sequence-function relationship of ribozymes and to efficiently engineer synthetic ribozymes, a large number of ribozyme variants need to be examined which was limited to hundreds of sequences by Sanger sequencing. The advent of high-throughput sequencing technologies, however, has allowed us to sequence millions of ribozyme sequences at low cost. This review focuses on the recent applications of high-throughput sequencing to both characterize and engineer ribozymes, to highlight how the large-scale sequence data can advance ribozyme research and engineering.
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Affiliation(s)
- Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan.
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44
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Hamachi K, Mutsuro-Aoki H, Tanizawa K, Hirasawa I, Umehara T, Tamura K. Effects of complementary loop composition in truncated R3C ligase ribozymes on kiss switch activation. Biosystems 2019; 177:9-15. [PMID: 30639771 DOI: 10.1016/j.biosystems.2019.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 12/24/2022]
Abstract
The formation of a kissing-loop through the introduction of complementary 7-membered loops is known to dramatically increase the activity of truncated R3C ligase ribozymes that otherwise display reduced activity. Restoration of activity is thought to result from kissing complex formation-induced rearrangement of two molecules with complementary loops. By combining two types of R3C ligase ribozyme mutants, <A> and <hairpin-ΔU>, the influence of loop composition on ligation activity was investigated. Substrate ligation occurred in <hairpin-ΔU>, but not in <A>, despite the absence of a substrate-binding site in <hairpin-ΔU>. Loop-loop interactions of <A>- and <hairpin-ΔU>-variants with complementary 6-membered loops also resulted in proper kissing-complex formation-induced substrate ligation. However, heterogeneous combinations of 7- and 6-membered loops, and/or of 6- and 5-membered loops had distinct results that depended upon the sequence and bulged nucleotides of the loop regions. These differences suggest that both thermodynamic and kinetic controls act upon the kissing-loop interaction-mediated rearrangement of the shortened trans-R3C ribozymes.
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Affiliation(s)
- Kokoro Hamachi
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Hiromi Mutsuro-Aoki
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Kana Tanizawa
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Ito Hirasawa
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Takuya Umehara
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Koji Tamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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Mutschler H, Taylor AI, Porebski BT, Lightowlers A, Houlihan G, Abramov M, Herdewijn P, Holliger P. Random-sequence genetic oligomer pools display an innate potential for ligation and recombination. eLife 2018; 7:43022. [PMID: 30461419 PMCID: PMC6289569 DOI: 10.7554/elife.43022] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 11/16/2018] [Indexed: 02/06/2023] Open
Abstract
Recombination, the exchange of information between different genetic polymer strands, is of fundamental importance in biology for genome maintenance and genetic diversification and is mediated by dedicated recombinase enzymes. Here, we describe an innate capacity for non-enzymatic recombination (and ligation) in random-sequence genetic oligomer pools. Specifically, we examine random and semi-random eicosamer (N20) pools of RNA, DNA and the unnatural genetic polymers ANA (arabino-), HNA (hexitol-) and AtNA (altritol-nucleic acids). While DNA, ANA and HNA pools proved inert, RNA (and to a lesser extent AtNA) pools displayed diverse modes of spontaneous intermolecular recombination, connecting recombination mechanistically to the vicinal ring cis-diol configuration shared by RNA and AtNA. Thus, the chemical constitution that renders both susceptible to hydrolysis emerges as the fundamental determinant of an innate capacity for recombination, which is shown to promote a concomitant increase in compositional, informational and structural pool complexity and hence evolutionary potential.
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Affiliation(s)
| | | | | | | | | | - Mikhail Abramov
- REGA Institute, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Piet Herdewijn
- REGA Institute, Katholieke Universiteit Leuven, Leuven, Belgium
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Shelke SA, Shao Y, Laski A, Koirala D, Weissman BP, Fuller JR, Tan X, Constantin TP, Waggoner AS, Bruchez MP, Armitage BA, Piccirilli JA. Structural basis for activation of fluorogenic dyes by an RNA aptamer lacking a G-quadruplex motif. Nat Commun 2018; 9:4542. [PMID: 30382099 PMCID: PMC6208384 DOI: 10.1038/s41467-018-06942-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 09/26/2018] [Indexed: 12/24/2022] Open
Abstract
The DIR2s RNA aptamer, a second-generation, in-vitro selected binder to dimethylindole red (DIR), activates the fluorescence of cyanine dyes, DIR and oxazole thiazole blue (OTB), allowing detection of two well-resolved emission colors. Using Fab BL3-6 and its cognate hairpin as a crystallization module, we solved the crystal structures of both the apo and OTB-SO3 bound forms of DIR2s at 2.0 Å and 1.8 Å resolution, respectively. DIR2s adopts a compact, tuning fork-like architecture comprised of a helix and two short stem-loops oriented in parallel to create the ligand binding site through tertiary interactions. The OTB-SO3 fluorophore binds in a planar conformation to a claw-like structure formed by a purine base-triple, which provides a stacking platform for OTB-SO3, and an unpaired nucleotide, which partially caps the binding site from the top. The absence of a G-quartet or base tetrad makes the DIR2s aptamer unique among fluorogenic RNAs with known 3D structure. The DIR2s RNA aptamer activates the fluorescence of cyanine dyes allowing detection of two well-resolved emission colors. Here authors solve the crystal structures of the apo and OTB-SO3 fluorophore-bound DIR2s and show how the fluorophore ligand is bound.
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Affiliation(s)
- Sandip A Shelke
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Yaming Shao
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Artur Laski
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Deepak Koirala
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | | | - James R Fuller
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Xiaohong Tan
- Center for Nucleic Acids Science and Technology, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Tudor P Constantin
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Alan S Waggoner
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Marcel P Bruchez
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Bruce A Armitage
- Center for Nucleic Acids Science and Technology, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Joseph A Piccirilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA. .,Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA.
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Models of Replicator Proliferation Involving Differential Replicator Subunit Stability. ORIGINS LIFE EVOL B 2018; 48:331-342. [PMID: 30203409 DOI: 10.1007/s11084-018-9561-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/22/2018] [Indexed: 10/28/2022]
Abstract
Several models for the origin of life involve molecules that are capable of self-replication, such as self-replicating polymers composed of RNA or DNA or amino acids. Here we consider a hypothetical replicator (AB) composed of two subunits, A and B. Programs written in Python and C programming languages were used to model AB replicator abundance as a function of cycles of replication (iterations), under specified hypothetical conditions. Two non-exclusive models describe how a reduced stability for B relative to A can have an advantage for replicator activity and/or evolution by generating free A subunits. In model 1, free A subunits associate with AB replicators to create AAB replicators with greater activity. In simulations, reduced stability of B was beneficial when the replication activity of AAB was greater than two times the replication activity of AB. In model 2, the free A subunit is inactive for some number of iterations before it re-creates the B subunit. A re-creates the B subunit with an equal chance of creating B or B', where B' is a mutant that increases AB' replicator activity relative to AB. In simulations, at moderate number of iterations (< 15), a shorter survival time for B is beneficial when the stability of B is greater than the inactive time of A. The results are consistent with the hypothesis that reduced stability for a replicator subunit can be advantageous under appropriate conditions.
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Abstract
The general notion of an "RNA world" is that, in the early development of life on the Earth, genetic continuity was assured by the replication of RNA, and RNA molecules were the chief agents of catalytic function. Assuming that all of the components of RNA were available in some prebiotic locale, these components could have assembled into activated nucleotides that condensed to form RNA polymers, setting the stage for the chemical replication of polynucleotides through RNA-templated RNA polymerization. If a sufficient diversity of RNAs could be copied with reasonable rate and fidelity, then Darwinian evolution would begin with RNAs that facilitated their own reproduction enjoying a selective advantage. The concept of a "protocell" refers to a compartment where replication of the primitive genetic material took place and where primitive catalysts gave rise to products that accumulated locally for the benefit of the replicating cellular entity. Replication of both the protocell and its encapsulated genetic material would have enabled natural selection to operate based on the differential fitness of competing cellular entities, ultimately giving rise to modern cellular life.
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Affiliation(s)
- Gerald F Joyce
- The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Jack W Szostak
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114
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Tanizawa K, Uchida S, Kurihara E, Umehara T, Tamura K. The Kiss Switch Brings Inactive R3C Ligase Ribozyme Back to Life. BIOLOGY 2018; 7:E7. [PMID: 29315240 PMCID: PMC5872033 DOI: 10.3390/biology7010007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 11/16/2022]
Abstract
R3C ligase ribozyme catalyzes the nucleophilic attack by a 3'-hydroxyl on a 5'-α-phosphorus of triphosphates to form a 3'-5'-phosphodiester bond. In the present study, although the truncation of R3C ribozyme was accompanied by a large reduction in ligation activity (decrease by two orders of magnitude compared to that of the ligated product of full-length R3C ribozyme after 18.5 h at 23 °C), the introduction of complementary seven-membered kissing-loops served as a "switch" to reactivate the truncated R3C ribozyme with approximately one-fifth of the activity of the full-length R3C ribozyme. This reactivation occurred in a trans-manner, and the grip region and substrate-binding site of the truncated R3C ribozyme were necessary to locate the substrate in the proper position for ligation with the other molecule. Reactivation resulted from complex tertiary interactions between two ribozymes, including kissing-loop interaction-induced annealing and the formation of a stable duplex. The drastic increase of the activity of poorly active ribozymes through the kissing-loop interaction may provide an important clue into the acquisition of substantial activity during the evolution of the RNA world.
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Affiliation(s)
- Kana Tanizawa
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Sayuri Uchida
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Eri Kurihara
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Takuya Umehara
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Koji Tamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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Staroseletz Y, Nechaev S, Bichenkova E, Bryce RA, Watson C, Vlassov V, Zenkova M. Non-enzymatic recombination of RNA: Ligation in loops. Biochim Biophys Acta Gen Subj 2017; 1862:705-725. [PMID: 29097301 DOI: 10.1016/j.bbagen.2017.10.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/10/2017] [Accepted: 10/26/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND While the RNA world hypothesis is widely accepted, it is still far from complete: the existence of self-replicating ribozyme, consisting of potentially hundreds of nucleotides, is a core assumption for the majority of RNA world models. The appearance of such long RNA molecules under prebiotic conditions is not self-evident. Recombination seems to be a plausible way of creating RNA diversity, resulting in the appearance of functional RNAs, capable of self-replicating. METHODS We report here on the study of recombination process modelled with two 96 nts RNA fragments. Detection of recombination products was performed with RT-PCR followed by TA-cloning and Sanger sequencing. RESULTS A wide range of recombinant products was detected. We found that (i) the most efficient ligation was observed for RNA species forming bulges or internal loops, with ligation partners located within the loop; (ii) a strong preference was observed for formation of a few types of major products with a large variety of minor products; (iii) ligation could occur with participation of either 2',3'-cyclophosphate or 5'-ppp; (iv) the presence of key reaction components, i.e. 5'ppp-RNAs, enabled the formation of additional types of product; (v) molecular dynamics simulations of one of the most abundant products suggests that the ligation results in a preferable formation of 2'-5'- rather than 3'-5'-linkages. CONCLUSIONS The study demonstrates regularities of new RNA molecules formation with non-enzymatic recombination process. GENERAL SIGNIFICANCE Our findings provide new data supporting the RNA World hypothesis and show the way of new RNA sequences emergence under prebiotic conditions.
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Affiliation(s)
- Yaroslav Staroseletz
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Sergey Nechaev
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Elena Bichenkova
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Richard A Bryce
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Catherine Watson
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Valentin Vlassov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Marina Zenkova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia.
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