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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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2
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McRae EKS, Wan CJK, Kristoffersen EL, Hansen K, Gianni E, Gallego I, Curran JF, Attwater J, Holliger P, Andersen ES. Cryo-EM structure and functional landscape of an RNA polymerase ribozyme. Proc Natl Acad Sci U S A 2024; 121:e2313332121. [PMID: 38207080 PMCID: PMC10801858 DOI: 10.1073/pnas.2313332121] [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: 08/09/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
The emergence of an RNA replicase capable of self-replication is considered an important stage in the origin of life. RNA polymerase ribozymes (PR) - including a variant that uses trinucleotide triphosphates (triplets) as substrates - have been created by in vitro evolution and are the closest functional analogues of the replicase, but the structural basis for their function is poorly understood. Here we use single-particle cryogenic electron microscopy (cryo-EM) and high-throughput mutation analysis to obtain the structure of a triplet polymerase ribozyme (TPR) apoenzyme and map its functional landscape. The cryo-EM structure at 5-Å resolution reveals the TPR as an RNA heterodimer comprising a catalytic subunit and a noncatalytic, auxiliary subunit, resembling the shape of a left hand with thumb and fingers at a 70° angle. The two subunits are connected by two distinct kissing-loop (KL) interactions that are essential for polymerase function. Our combined structural and functional data suggest a model for templated RNA synthesis by the TPR holoenzyme, whereby heterodimer formation and KL interactions preorganize the TPR for optimal primer-template duplex binding, triplet substrate discrimination, and templated RNA synthesis. These results provide a better understanding of TPR structure and function and should aid the engineering of more efficient PRs.
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Affiliation(s)
- Ewan K. S. McRae
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University, Aarhus8000, Denmark
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Christopher J. K. Wan
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Emil L. Kristoffersen
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University, Aarhus8000, Denmark
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Kalinka Hansen
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University, Aarhus8000, Denmark
| | - Edoardo Gianni
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Isaac Gallego
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Joseph F. Curran
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - James Attwater
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Philipp Holliger
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council, Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Ebbe S. Andersen
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University, Aarhus8000, Denmark
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3
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Sweeney KJ, Han X, Müller UF. A ribozyme that uses lanthanides as cofactor. Nucleic Acids Res 2023; 51:7163-7173. [PMID: 37326001 PMCID: PMC10415125 DOI: 10.1093/nar/gkad513] [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: 10/03/2022] [Revised: 05/10/2023] [Accepted: 06/13/2023] [Indexed: 06/17/2023] Open
Abstract
To explore how an early, RNA-based life form could have functioned, in vitro selection experiments have been used to develop catalytic RNAs (ribozymes) with relevant functions. We previously identified ribozymes that use the prebiotically plausible energy source cyclic trimetaphosphate (cTmp) to convert their 5'-hydroxyl group to a 5'-triphosphate. While these ribozymes were developed in the presence of Mg2+, we tested here whether lanthanides could also serve as catalytic cofactors because lanthanides are ideal catalytic cations for this reaction. After an in vitro selection in the presence of Yb3+, several active sequences were isolated, and the most active RNA was analyzed in more detail. This ribozyme required lanthanides for activity, with highest activity at a 10:1 molar ratio of cTmp : Yb3+. Only the four heaviest lanthanides gave detectable signals, indicating a high sensitivity of ribozyme catalysis to the lanthanide ion radius. Potassium and Magnesium did not facilitate catalysis alone but they increased the lanthanide-mediated kOBS by at least 100-fold, with both K+ and Mg2+ modulating the ribozyme's secondary structure. Together, these findings show that RNA is able to use the unique properties of lanthanides as catalytic cofactor. The results are discussed in the context of early life forms.
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Affiliation(s)
- Kevin J Sweeney
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Xu Han
- 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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4
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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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5
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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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Tsue AF, Kania EE, Lei DQ, Fields R, McGann CD, Hershberg E, Deng X, Kihiu M, Ong SE, Disteche CM, Kugel S, Beliveau BJ, Schweppe DK, Shechner DM. Oligonucleotide-directed proximity-interactome mapping (O-MAP): A unified method for discovering RNA-interacting proteins, transcripts and genomic loci in situ. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.19.524825. [PMID: 36711823 PMCID: PMC9882335 DOI: 10.1101/2023.01.19.524825] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Throughout biology, RNA molecules form complex networks of molecular interactions that are central to their function, but remain challenging to investigate. Here, we introduce Oligonucleotide-mediated proximity-interactome MAPping (O-MAP), a straightforward method for elucidating the biomolecules near an RNA of interest, within its native cellular context. O-MAP uses programmable oligonucleotide probes to deliver proximity-biotinylating enzymes to a target RNA, enabling nearby molecules to be enriched by streptavidin pulldown. O-MAP induces exceptionally precise RNA-localized in situ biotinylation, and unlike alternative methods it enables straightforward optimization of its targeting accuracy. Using the 47S pre-ribosomal RNA and long noncoding RNA Xist as models, we develop O-MAP workflows for unbiased discovery of RNA-proximal proteins, transcripts, and genomic loci. This revealed unexpected co-compartmentalization of Xist and other chromatin-regulatory RNAs and enabled systematic characterization of nucleolar-chromatin interactions across multiple cell lines. O-MAP is portable to cultured cells, organoids, and tissues, and to RNAs of various lengths, abundances, and sequence composition. And, O-MAP requires no genetic manipulation and uses exclusively off-the-shelf parts. We therefore anticipate its application to a broad array of RNA phenomena.
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7
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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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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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9
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Kundu N, Mondal D, Sarkar N. Dynamics of the vesicles composed of fatty acids and other amphiphile mixtures: unveiling the role of fatty acids as a model protocell membrane. Biophys Rev 2020; 12:1117-1131. [PMID: 32926295 PMCID: PMC7575682 DOI: 10.1007/s12551-020-00753-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/03/2020] [Indexed: 01/31/2023] Open
Abstract
Fundamental research at the interface of chemistry and biology has the potential to shine light on the question of how living cells can be synthesized from inanimate matter thereby providing plausible pathways for the emergence of cellular life. Compartmentalization of different biochemical reactions within a membrane bound water environment is considered an essential first step in any origin of life pathway. It has been suggested that fatty acid-based vesicles can be considered a model protocell having the potential for change via Darwinian evolution. As such, protocell models have the potential to assist in furthering our understanding of the origin of life in the laboratory. Fatty acids, both by themselves and in mixtures with other amphiphiles, can form different self-assembled structures depending on their surroundings. Recent studies of fatty acid-based membranes have suggested likely pathways of protocell growth, division and membrane permeabilisation for the transport of different nutrients, such as nucleotides across the membrane. In this review, different dynamic processes related to the growth and division of the protocell membrane are discussed and possible pathways for transition of the protocell to the modern cell are explored. These areas of research may lead to a better understanding of the synthesis of artificial cell-like entities and thus herald the possibility of creating new form of life distinct from existing biology. Graphical Abstract Table of Content (TOC) only.
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Affiliation(s)
- Niloy Kundu
- Environment Research Group, R&D Department, Tata Steel Ltd, Jamshedpur, 831007, India.
| | - Dipankar Mondal
- Institute for System Genetics and Department of Cell Biology, New York University, Langone Medical Center, New York, 10016, USA
- Department of Chemistry, Indian Institute of Technology, Kharagpur, WB, 721302, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur, WB, 721302, India
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Micura R, Höbartner C. Fundamental studies of functional nucleic acids: aptamers, riboswitches, ribozymes and DNAzymes. Chem Soc Rev 2020; 49:7331-7353. [PMID: 32944725 DOI: 10.1039/d0cs00617c] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review aims at juxtaposing common versus distinct structural and functional strategies that are applied by aptamers, riboswitches, and ribozymes/DNAzymes. Focusing on recently discovered systems, we begin our analysis with small-molecule binding aptamers, with emphasis on in vitro-selected fluorogenic RNA aptamers and their different modes of ligand binding and fluorescence activation. Fundamental insights are much needed to advance RNA imaging probes for detection of exo- and endogenous RNA and for RNA process tracking. Secondly, we discuss the latest gene expression-regulating mRNA riboswitches that respond to the alarmone ppGpp, to PRPP, to NAD+, to adenosine and cytidine diphosphates, and to precursors of thiamine biosynthesis (HMP-PP), and we outline new subclasses of SAM and tetrahydrofolate-binding RNA regulators. Many riboswitches bind protein enzyme cofactors that, in principle, can catalyse a chemical reaction. For RNA, however, only one system (glmS ribozyme) has been identified in Nature thus far that utilizes a small molecule - glucosamine-6-phosphate - to participate directly in reaction catalysis (phosphodiester cleavage). We wonder why that is the case and what is to be done to reveal such likely existing cellular activities that could be more diverse than currently imagined. Thirdly, this brings us to the four latest small nucleolytic ribozymes termed twister, twister-sister, pistol, and hatchet as well as to in vitro selected DNA and RNA enzymes that promote new chemistry, mainly by exploiting their ability for RNA labelling and nucleoside modification recognition. Enormous progress in understanding the strategies of nucleic acids catalysts has been made by providing thorough structural fundaments (e.g. first structure of a DNAzyme, structures of ribozyme transition state mimics) in combination with functional assays and atomic mutagenesis.
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Affiliation(s)
- Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University Innsbruck, Innsbruck, Austria.
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11
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Walton T, DasGupta S, Duzdevich D, Oh SS, Szostak JW. In vitro selection of ribozyme ligases that use prebiotically plausible 2-aminoimidazole-activated substrates. Proc Natl Acad Sci U S A 2020; 117:5741-5748. [PMID: 32123094 PMCID: PMC7084097 DOI: 10.1073/pnas.1914367117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The hypothesized central role of RNA in the origin of life suggests that RNA propagation predated the advent of complex protein enzymes. A critical step of RNA replication is the template-directed synthesis of a complementary strand. Two experimental approaches have been extensively explored in the pursuit of demonstrating protein-free RNA synthesis: template-directed nonenzymatic RNA polymerization using intrinsically reactive monomers and ribozyme-catalyzed polymerization using more stable substrates such as biological 5'-triphosphates. Despite significant progress in both approaches in recent years, the assembly and copying of functional RNA sequences under prebiotic conditions remains a challenge. Here, we explore an alternative approach to RNA-templated RNA copying that combines ribozyme catalysis with RNA substrates activated with a prebiotically plausible leaving group, 2-aminoimidazole (2AI). We applied in vitro selection to identify ligase ribozymes that catalyze phosphodiester bond formation between a template-bound primer and a phosphor-imidazolide-activated oligomer. Sequencing revealed the progressive enrichment of 10 abundant sequences from a random sequence pool. Ligase activity was detected in all 10 RNA sequences; all required activation of the ligator with 2AI and generated a 3'-5' phosphodiester bond. We propose that ribozyme catalysis of phosphodiester bond formation using intrinsically reactive RNA substrates, such as imidazolides, could have been an evolutionary step connecting purely nonenzymatic to ribozyme-catalyzed RNA template copying during the origin of life.
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Affiliation(s)
- Travis Walton
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
| | - Saurja DasGupta
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
| | - Daniel Duzdevich
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
| | - Seung Soo Oh
- Department of Materials Science and Engineering, Pohang University of Science and Technology, 37673 Pohang, Gyeongbuk, South Korea
| | - Jack W Szostak
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114;
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
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12
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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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13
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An artificial DNAzyme RNA ligase shows a reaction mechanism resembling that of cellular polymerases. Nat Catal 2019. [DOI: 10.1038/s41929-019-0290-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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14
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Vandevenne M, Delmarcelle M, Galleni M. RNA Regulatory Networks as a Control of Stochasticity in Biological Systems. Front Genet 2019; 10:403. [PMID: 31134128 PMCID: PMC6514243 DOI: 10.3389/fgene.2019.00403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/12/2019] [Indexed: 01/24/2023] Open
Abstract
The discovery that the non-protein coding part of human genome, dismissed as "junk DNA," is actively transcripted and carries out crucial functions is probably one of the most important discoveries of the past decades. These transcripts are becoming the rising stars of modern biology. In this review, we have casted a new light on RNAs. We have placed these molecules in the context of life origins, evolution with a big emphasize on the "RNA networks" concept. We discuss how this view can help us to understand the global role of RNA networks in modern cells, and can change our perception of the cell biology and therapy. Finally, although high-throughput methods as well as traditional case-to-case studies have laid the groundwork for our current knowledge of transcriptomes, we would like to discuss new strategies that are better suited to uncover and tackle these integrated and complex RNA networks.
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Affiliation(s)
- Marylène Vandevenne
- InBioS - Center for Protein Engineering, University of Liège, Liège, Belgium
| | - Michael Delmarcelle
- InBioS - Center for Protein Engineering, University of Liège, Liège, Belgium
| | - Moreno Galleni
- InBioS - Center for Protein Engineering, University of Liège, Liège, Belgium
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15
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Takahashi S, Okura H, Sugimoto N. Bisubstrate Function of RNA Polymerases Triggered by Molecular Crowding Conditions. Biochemistry 2019; 58:1081-1093. [DOI: 10.1021/acs.biochem.8b01204] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Kobe 650-0047, Japan
| | - Hiromichi Okura
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Kobe 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Kobe 650-0047, Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 minatojima-Minamimachi, Kobe 650-0047, Japan
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16
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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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17
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Kunnev D, Gospodinov A. Possible Emergence of Sequence Specific RNA Aminoacylation via Peptide Intermediary to Initiate Darwinian Evolution and Code Through Origin of Life. Life (Basel) 2018; 8:E44. [PMID: 30279401 PMCID: PMC6316189 DOI: 10.3390/life8040044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/30/2018] [Accepted: 09/30/2018] [Indexed: 12/12/2022] Open
Abstract
One of the most intriguing questions in biological science is how life originated on Earth. A large number of hypotheses have been proposed to explain it, each putting an emphasis on different events leading to functional translation and self-sustained system. Here, we propose a set of interactions that could have taken place in the prebiotic environment. According to our hypothesis, hybridization-induced proximity of short aminoacylated RNAs led to the synthesis of peptides of random sequence. We postulate that among these emerged a type of peptide(s) capable of stimulating the interaction between specific RNAs and specific amino acids, which we call "bridge peptide" (BP). We conclude that translation should have emerged at the same time when the standard genetic code begun to evolve due to the stabilizing effect on RNA-peptide complexes with the help of BPs. Ribosomes, ribozymes, and the enzyme-directed RNA replication could co-evolve within the same period, as logical outcome of RNA-peptide world without the need of RNA only self-sustained step.
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Affiliation(s)
- Dimiter Kunnev
- Roswell Park Cancer Institute, Department of Molecular & Cellular Biology, Buffalo, NY 14263, USA.
| | - Anastas Gospodinov
- Roumen Tsanev Institute of Molecular Biology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. 21, Sofia 1113, Bulgaria.
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18
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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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19
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Choi SJ, Ban C. Crystal structure of a DNA aptamer bound to PvLDH elucidates novel single-stranded DNA structural elements for folding and recognition. Sci Rep 2016; 6:34998. [PMID: 27725738 PMCID: PMC5057103 DOI: 10.1038/srep34998] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/22/2016] [Indexed: 02/07/2023] Open
Abstract
Structural elements are key elements for understanding single-stranded nucleic acid folding. Although various RNA structural elements have been documented, structural elements of single-stranded DNA (ssDNA) have rarely been reported. Herein, we determined a crystal structure of PvLDH in complex with a DNA aptamer called pL1. This aptamer folds into a hairpin-bulge contact by adopting three novel structural elements, viz, DNA T-loop-like motif, base-phosphate zipper, and DNA G·G metal ion zipper. Moreover, the pL1:PvLDH complex shows unique properties compared with other protein:nucleic acid complexes. Generally, extensive intermolecular hydrogen bonds occur between unpaired nucleotides and proteins for specific recognitions. Although most protein-interacting nucleotides of pL1 are unpaired nucleotides, pL1 recognizes PvLDH by predominant shape complementarity with many bridging water molecules owing to the combination of three novel structural elements making protein-binding unpaired nucleotides stable. Moreover, the additional set of Plasmodium LDH residues which were shown to form extensive hydrogen bonds with unpaired nucleotides of 2008s does not participate in the recognition of pL1. Superimposition of the pL1:PvLDH complex with hLDH reveals steric clashes between pL1 and hLDH in contrast with no steric clashes between 2008s and hLDH. Therefore, specific protein recognition mode of pL1 is totally different from that of 2008s.
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Affiliation(s)
- Sung-Jin Choi
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, South Korea
| | - Changill Ban
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, South Korea
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20
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Casalino L, Magistrato A. Structural, dynamical and catalytic interplay between Mg2+ ions and RNA. Vices and virtues of atomistic simulations. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.02.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Rana AK, Ankri S. Reviving the RNA World: An Insight into the Appearance of RNA Methyltransferases. Front Genet 2016; 7:99. [PMID: 27375676 PMCID: PMC4893491 DOI: 10.3389/fgene.2016.00099] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/23/2016] [Indexed: 12/13/2022] Open
Abstract
RNA, the earliest genetic and catalytic molecule, has a relatively delicate and labile chemical structure, when compared to DNA. It is prone to be damaged by alkali, heat, nucleases, or stress conditions. One mechanism to protect RNA or DNA from damage is through site-specific methylation. Here, we propose that RNA methylation began prior to DNA methylation in the early forms of life evolving on Earth. In this article, the biochemical properties of some RNA methyltransferases (MTases), such as 2′-O-MTases (Rlml/RlmN), spOUT MTases and the NSun2 MTases are dissected for the insight they provide on the transition from an RNA world to our present RNA/DNA/protein world.
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Affiliation(s)
- Ajay K Rana
- Division of Biology, State Forensic Science Laboratory, Ministry of Home Affairs, Government of Jharkhand Ranchi, India
| | - Serge Ankri
- Department of Molecular Microbiology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion Israel Institute of Technology Haifa, Israel
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22
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Crystal structure of a DNA catalyst. Nature 2016; 529:231-4. [PMID: 26735012 DOI: 10.1038/nature16471] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/20/2015] [Indexed: 01/13/2023]
Abstract
Catalysis in biology is restricted to RNA (ribozymes) and protein enzymes, but synthetic biomolecular catalysts can also be made of DNA (deoxyribozymes) or synthetic genetic polymers. In vitro selection from synthetic random DNA libraries identified DNA catalysts for various chemical reactions beyond RNA backbone cleavage. DNA-catalysed reactions include RNA and DNA ligation in various topologies, hydrolytic cleavage and photorepair of DNA, as well as reactions of peptides and small molecules. In spite of comprehensive biochemical studies of DNA catalysts for two decades, fundamental mechanistic understanding of their function is lacking in the absence of three-dimensional models at atomic resolution. Early attempts to solve the crystal structure of an RNA-cleaving deoxyribozyme resulted in a catalytically irrelevant nucleic acid fold. Here we report the crystal structure of the RNA-ligating deoxyribozyme 9DB1 (ref. 14) at 2.8 Å resolution. The structure captures the ligation reaction in the post-catalytic state, revealing a compact folding unit stabilized by numerous tertiary interactions, and an unanticipated organization of the catalytic centre. Structure-guided mutagenesis provided insights into the basis for regioselectivity of the ligation reaction and allowed remarkable manipulation of substrate recognition and reaction rate. Moreover, the structure highlights how the specific properties of deoxyribose are reflected in the backbone conformation of the DNA catalyst, in support of its intricate three-dimensional organization. The structural principles underlying the catalytic ability of DNA elucidate differences and similarities in DNA versus RNA catalysts, which is relevant for comprehending the privileged position of folded RNA in the prebiotic world and in current organisms.
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23
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Multiplexable, locus-specific targeting of long RNAs with CRISPR-Display. Nat Methods 2015; 12:664-70. [PMID: 26030444 PMCID: PMC4821475 DOI: 10.1038/nmeth.3433] [Citation(s) in RCA: 219] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 05/08/2015] [Indexed: 12/26/2022]
Abstract
Noncoding RNAs (ncRNAs) comprise an important class of regulatory molecules that mediate a vast array of biological processes. This broad functional capacity has also facilitated the design of artificial ncRNAs with novel functions. To further investigate and harness these capabilities, we developed CRISPR-Display (“CRISP-Disp”), a targeted localization method that uses Sp. Cas9 to deploy large RNA cargos to DNA loci. We demonstrate that exogenous RNA domains can be functionally appended onto the CRISPR scaffold at multiple insertion points, allowing the construction of Cas9 complexes with protein-binding cassettes, artificial aptamers, pools of random sequences, and RNAs up to 4.8 kilobases in length, including natural lncRNAs. Unlike most existing CRISPR methods, CRISP-Disp allows simultaneous multiplexing of distinct functions at multiple targets, limited only by the number of available functional RNA motifs. We anticipate that this technology will provide a powerful method with which to ectopically localize functional RNAs and ribonucleoprotein (RNP) complexes at specified genomic loci.
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24
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Abstract
An RNA World that predated the modern world of polypeptide and polynucleotide is one of the most widely accepted models in origin of life research. In this model, the translation system shepherded the RNA World into the extant biology of DNA, RNA, and protein. Here, we examine the RNA World Hypothesis in the context of increasingly detailed information available about the origins, evolution, functions, and mechanisms of the translation system. We conclude that the translation system presents critical challenges to RNA World Hypotheses. Firstly, a timeline of the RNA World is problematic when the ribosome is incorporated. The mechanism of peptidyl transfer of the ribosome appears distinct from evolved enzymes, signaling origins in a chemical rather than biological milieu. Secondly, we have no evidence that the basic biochemical toolset of life is subject to substantive change by Darwinian evolution, as required for the transition from the RNA world to extant biology. Thirdly, we do not see specific evidence for biological takeover of ribozyme function by protein enzymes. Finally, we can find no basis for preservation of the ribosome as ribozyme or the universality of translation, if it were the case that other information transducing ribozymes, such as ribozyme polymerases, were replaced by protein analogs and erased from the phylogenetic record. We suggest that an updated model of the RNA World should address the current state of knowledge of the translation system.
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25
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Carter CW. What RNA World? Why a Peptide/RNA Partnership Merits Renewed Experimental Attention. Life (Basel) 2015; 5:294-320. [PMID: 25625599 PMCID: PMC4390853 DOI: 10.3390/life5010294] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/12/2015] [Indexed: 12/16/2022] Open
Abstract
We review arguments that biology emerged from a reciprocal partnership in which small ancestral oligopeptides and oligonucleotides initially both contributed rudimentary information coding and catalytic rate accelerations, and that the superior information-bearing qualities of RNA and the superior catalytic potential of proteins emerged from such complexes only with the gradual invention of the genetic code. A coherent structural basis for that scenario was articulated nearly a decade before the demonstration of catalytic RNA. Parallel hierarchical catalytic repertoires for increasingly highly conserved sequences from the two synthetase classes now increase the likelihood that they arose as translation products from opposite strands of a single gene. Sense/antisense coding affords a new bioinformatic metric for phylogenetic relationships much more distant than can be reconstructed from multiple sequence alignments of a single superfamily. Evidence for distinct coding properties in tRNA acceptor stems and anticodons, and experimental demonstration that the two synthetase family ATP binding sites can indeed be coded by opposite strands of the same gene supplement these biochemical and bioinformatic data, establishing a solid basis for key intermediates on a path from simple, stereochemically coded, reciprocally catalytic peptide/RNA complexes through the earliest peptide catalysts to contemporary aminoacyl-tRNA synthetases. That scenario documents a path to increasing complexity that obviates the need for a single polymer to act both catalytically and as an informational molecule.
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Affiliation(s)
- Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7260, USA.
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26
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Faehnle CR, Walleshauser J, Joshua-Tor L. Mechanism of Dis3l2 substrate recognition in the Lin28-let-7 pathway. Nature 2014; 514:252-256. [PMID: 25119025 PMCID: PMC4192074 DOI: 10.1038/nature13553] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/02/2014] [Indexed: 12/28/2022]
Abstract
The pluripotency factor Lin28 inhibits the biogenesis of the let-7 family of mammalian microRNAs1–4. Lin28 is highly expressed in embryonic stem cells and has a fundamental role in regulation of development5, glucose metabolism6 and tissue regeneration7. Alternatively, Lin28 overexpression is correlated with the onset of numerous cancers8, while let-7, a tumor suppressor, silences several human oncogenes5. Lin28 binds to precursor let-7 (pre-let-7) hairpins9, triggering the 3' oligo-uridylation activity of TUT4/710–12. The oligoU tail added to pre-let-7 serves as a decay signal, as it is rapidly degraded by Dis3L213,14, a homolog of the catalytic subunit of the RNA exosome. The molecular basis of Lin28 mediated recruitment of TUT4/7 to pre-let-7 and its subsequent degradation by Dis3L2 is largely unknown. To examine the mechanism of Dis3L2 substrate recognition we determined the structure of mouse Dis3L2 in complex with an oligoU RNA to mimic the uridylated tail of pre-let-7. Three RNA binding domains form an open funnel on one face of the catalytic domain that allows RNA to navigate a path to the active site different from its exosome counterpart. The resulting path reveals an extensive network of uracil-specific interactions spanning the first twelve nucleotides of an oligoU-tailed RNA. We identify three U-specificity zones that explain how Dis3L2 recognizes, binds and processes uridylated pre-let-7 in the final step of the Lin28/let-7 pathway.
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Affiliation(s)
- Christopher R Faehnle
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Jack Walleshauser
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Watson School of Biological Science 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Leemor Joshua-Tor
- W. M. Keck Structural Biology Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Watson School of Biological Science 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Howard Hughes Medical Institute 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.,Cold Spring Harbor Laboratory 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
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27
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Kurihara E, Uchida S, Umehara T, Tamura K. Development of a Functionally Minimized Mutant of the R3C Ligase Ribozyme Offers Insight into the Plausibility of the RNA World Hypothesis. BIOLOGY 2014; 3:452-65. [PMID: 25256424 PMCID: PMC4192621 DOI: 10.3390/biology3030452] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 07/14/2014] [Accepted: 07/22/2014] [Indexed: 11/17/2022]
Abstract
The R3C ligase ribozyme is an artificial ligase ribozyme produced by modification of the ribozyme that lacks cytidine. Here, we attempted to modify the original R3C ribozyme (73 nucleotides) by reducing the number of nucleotides while maintaining the maximum possible catalytic efficiency. By partially deleting both the "grip" (P4 + P5) and "hammer" (P3) stem-loops, we found the critical border to retain activity comparable to that of full-length R3C. The three-way junction structure was necessary to maintain enzymatic function and the stability of the "grip" (P4 + P5) stem had a large influence on the catalytic activity of R3C. The final minimized ribozyme we obtained comprised ~50 nucleotides, comparable to the estimated length of prebiotically synthesized RNA. Our findings suggest that the autocatalytic function in ribozymes is indeed possible to obtain using sequence lengths achievable with prebiotic synthesis.
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Affiliation(s)
- Eri Kurihara
- 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.
| | - 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.
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28
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Vidossich P, Magistrato A. QM/MM molecular dynamics studies of metal binding proteins. Biomolecules 2014; 4:616-45. [PMID: 25006697 PMCID: PMC4192665 DOI: 10.3390/biom4030616] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 11/16/2022] Open
Abstract
Mixed quantum-classical (quantum mechanical/molecular mechanical (QM/MM)) simulations have strongly contributed to providing insights into the understanding of several structural and mechanistic aspects of biological molecules. They played a particularly important role in metal binding proteins, where the electronic effects of transition metals have to be explicitly taken into account for the correct representation of the underlying biochemical process. In this review, after a brief description of the basic concepts of the QM/MM method, we provide an overview of its capabilities using selected examples taken from our work. Specifically, we will focus on heme peroxidases, metallo-β-lactamases, α-synuclein and ligase ribozymes to show how this approach is capable of describing the catalytic and/or structural role played by transition (Fe, Zn or Cu) and main group (Mg) metals. Applications will reveal how metal ions influence the formation and reduction of high redox intermediates in catalytic cycles and enhance drug metabolism, amyloidogenic aggregate formation and nucleic acid synthesis. In turn, it will become manifest that the protein frame directs and modulates the properties and reactivity of the metal ions.
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Affiliation(s)
- Pietro Vidossich
- Department of Chemistry, Autonomous University of Barcelona, 08193 Cerdanyola del Vallés, Spain.
| | - Alessandra Magistrato
- CNR-IOM-Democritos National Simulation Center c/o, International School for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34165 Trieste, Italy.
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29
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Abstract
The complexity of even the simplest known life forms makes efforts to synthesize living cells from inanimate components seem like a daunting task. However, recent progress toward the creation of synthetic cells, ranging from simple protocells to artificial cells approaching the complexity of bacteria, suggests that the synthesis of life is now a realistic goal. Protocell research, fueled by advances in the biophysics of primitive membranes and the chemistry of nucleic acid replication, is providing new insights into the origin of cellular life. Parallel efforts to construct more complex artificial cells, incorporating translational machinery and protein enzymes, are providing information about the requirements for protein-based life. We discuss recent advances and remaining challenges in the synthesis of artificial cells, the possibility of creating new forms of life distinct from existing biology, and the promise of this research for gaining a deeper understanding of the nature of living systems.
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Affiliation(s)
- J Craig Blain
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts 02114; ,
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30
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Ruiz-Mirazo K, Briones C, de la Escosura A. Prebiotic Systems Chemistry: New Perspectives for the Origins of Life. Chem Rev 2013; 114:285-366. [DOI: 10.1021/cr2004844] [Citation(s) in RCA: 563] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kepa Ruiz-Mirazo
- Biophysics
Unit (CSIC-UPV/EHU), Leioa, and Department of Logic and Philosophy
of Science, University of the Basque Country, Avenida de Tolosa 70, 20080 Donostia−San Sebastián, Spain
| | - Carlos Briones
- Department
of Molecular Evolution, Centro de Astrobiología (CSIC−INTA, associated to the NASA Astrobiology Institute), Carretera de Ajalvir, Km 4, 28850 Torrejón de Ardoz, Madrid, Spain
| | - Andrés de la Escosura
- Organic
Chemistry Department, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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31
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Attwater J, Wochner A, Holliger P. In-ice evolution of RNA polymerase ribozyme activity. Nat Chem 2013; 5:1011-8. [PMID: 24256864 DOI: 10.1038/nchem.1781] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 09/10/2013] [Indexed: 01/13/2023]
Abstract
Mechanisms of molecular self-replication have the potential to shed light on the origins of life. In particular, self-replication through RNA-catalysed templated RNA synthesis is thought to have supported a primordial 'RNA world'. However, existing polymerase ribozymes lack the capacity to synthesize RNAs approaching their own size. Here, we report the in vitro evolution of such catalysts directly in the RNA-stabilizing medium of water ice, which yielded RNA polymerase ribozymes specifically adapted to sub-zero temperatures and able to synthesize RNA in ices at temperatures as low as -19 °C. The combination of cold-adaptive mutations with a previously described 5' extension operating at ambient temperatures enabled the design of a first polymerase ribozyme capable of catalysing the accurate synthesis of an RNA sequence longer than itself (adding up to 206 nucleotides), an important stepping stone towards RNA self-replication.
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Affiliation(s)
- James Attwater
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
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32
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Usui K, Ichihashi N, Kazuta Y, Matsuura T, Yomo T. Kinetic model of double-stranded RNA formation during long RNA replication by Qβ replicase. FEBS Lett 2013; 587:2565-71. [DOI: 10.1016/j.febslet.2013.06.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/29/2013] [Accepted: 06/25/2013] [Indexed: 11/28/2022]
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33
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Attwater J, Tagami S, Kimoto M, Butler K, Kool ET, Wengel J, Herdewijn P, Hirao I, Holliger P. Chemical fidelity of an RNA polymerase ribozyme. Chem Sci 2013. [DOI: 10.1039/c3sc50574j] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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