1
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Colee C, Oberlag NM, Simon M, Chapman OS, Flanagan LC, Reid-McLaughlin ES, Gewing-Mullins JA, Maiche S, Patel DF, Cavalcanti ARO, Leconte AM. Discovery of Red-Shifting Mutations in Firefly Luciferase Using High-Throughput Biochemistry. Biochemistry 2024; 63:733-742. [PMID: 38437583 PMCID: PMC10956436 DOI: 10.1021/acs.biochem.3c00708] [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: 12/15/2023] [Revised: 02/03/2024] [Accepted: 02/20/2024] [Indexed: 03/06/2024]
Abstract
Photinus pyralis luciferase (FLuc) has proven a valuable tool for bioluminescence imaging, but much of the light emitted from the native enzyme is absorbed by endogenous biomolecules. Thus, luciferases displaying red-shifted emission enable higher resolution during deep-tissue imaging. A robust model of how protein structure determines emission color would greatly aid the engineering of red-shifted mutants, but no consensus has been reached to date. In this work, we applied deep mutational scanning to systematically assess 20 functionally important amino acid positions on FLuc for red-shifting mutations, predicting that an unbiased approach would enable novel contributions to this debate. We report dozens of red-shifting mutations as a result, a large majority of which have not been previously identified. Further characterization revealed that mutations N229T and T352M, in particular, bring about unimodal emission with the majority of photons being >600 nm. The red-shifting mutations identified by this high-throughput approach provide strong biochemical evidence for the multiple-emitter mechanism of color determination and point to the importance of a water network in the enzyme binding pocket for altering the emitter ratio. This work provides a broadly applicable mutational data set tying FLuc structure to emission color that contributes to our mechanistic understanding of emission color determination and should facilitate further engineering of improved probes for deep-tissue imaging.
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Affiliation(s)
- Clair
M. Colee
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Nicole M. Oberlag
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Marcell Simon
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Owen S. Chapman
- Department
of Biology, Pomona College, Claremont, California 91711, United States
| | - Lyndsey C. Flanagan
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Edison S. Reid-McLaughlin
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Jordan A. Gewing-Mullins
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Synaida Maiche
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | - Devi F. Patel
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
| | | | - Aaron M. Leconte
- W.M.
Keck Science Department of Claremont McKenna, Pitzer, and Scripps
Colleges, Claremont, California 91711, United States
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2
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Gaudêncio SP, Bayram E, Lukić Bilela L, Cueto M, Díaz-Marrero AR, Haznedaroglu BZ, Jimenez C, Mandalakis M, Pereira F, Reyes F, Tasdemir D. Advanced Methods for Natural Products Discovery: Bioactivity Screening, Dereplication, Metabolomics Profiling, Genomic Sequencing, Databases and Informatic Tools, and Structure Elucidation. Mar Drugs 2023; 21:md21050308. [PMID: 37233502 DOI: 10.3390/md21050308] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
Natural Products (NP) are essential for the discovery of novel drugs and products for numerous biotechnological applications. The NP discovery process is expensive and time-consuming, having as major hurdles dereplication (early identification of known compounds) and structure elucidation, particularly the determination of the absolute configuration of metabolites with stereogenic centers. This review comprehensively focuses on recent technological and instrumental advances, highlighting the development of methods that alleviate these obstacles, paving the way for accelerating NP discovery towards biotechnological applications. Herein, we emphasize the most innovative high-throughput tools and methods for advancing bioactivity screening, NP chemical analysis, dereplication, metabolite profiling, metabolomics, genome sequencing and/or genomics approaches, databases, bioinformatics, chemoinformatics, and three-dimensional NP structure elucidation.
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Affiliation(s)
- Susana P Gaudêncio
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
- UCIBIO-Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Engin Bayram
- Institute of Environmental Sciences, Room HKC-202, Hisar Campus, Bogazici University, Bebek, Istanbul 34342, Turkey
| | - Lada Lukić Bilela
- Department of Biology, Faculty of Science, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Mercedes Cueto
- Instituto de Productos Naturales y Agrobiología-CSIC, 38206 La Laguna, Spain
| | - Ana R Díaz-Marrero
- Instituto de Productos Naturales y Agrobiología-CSIC, 38206 La Laguna, Spain
- Instituto Universitario de Bio-Orgánica (IUBO), Universidad de La Laguna, 38206 La Laguna, Spain
| | - Berat Z Haznedaroglu
- Institute of Environmental Sciences, Room HKC-202, Hisar Campus, Bogazici University, Bebek, Istanbul 34342, Turkey
| | - Carlos Jimenez
- CICA- Centro Interdisciplinar de Química e Bioloxía, Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, HCMR Thalassocosmos, 71500 Gournes, Crete, Greece
| | - Florbela Pereira
- LAQV, REQUIMTE, Chemistry Department, NOVA School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Fernando Reyes
- Fundación MEDINA, Avda. del Conocimiento 34, 18016 Armilla, Spain
| | - Deniz Tasdemir
- GEOMAR Centre for Marine Biotechnology (GEOMAR-Biotech), Research Unit Marine Natural Products Chemistry, GEOMAR Helmholtz Centre for Ocean Research Kiel, Am Kiel-Kanal 44, 24106 Kiel, Germany
- Faculty of Mathematics and Natural Science, Kiel University, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
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3
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Janzen E, Shen Y, Vázquez-Salazar A, Liu Z, Blanco C, Kenchel J, Chen IA. Emergent properties as by-products of prebiotic evolution of aminoacylation ribozymes. Nat Commun 2022; 13:3631. [PMID: 35752631 PMCID: PMC9233669 DOI: 10.1038/s41467-022-31387-0] [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: 09/05/2021] [Accepted: 06/16/2022] [Indexed: 11/24/2022] Open
Abstract
Systems of catalytic RNAs presumably gave rise to important evolutionary innovations, such as the genetic code. Such systems may exhibit particular tolerance to errors (error minimization) as well as coding specificity. While often assumed to result from natural selection, error minimization may instead be an emergent by-product. In an RNA world, a system of self-aminoacylating ribozymes could enforce the mapping of amino acids to anticodons. We measured the activity of thousands of ribozyme mutants on alternative substrates (activated analogs for tryptophan, phenylalanine, leucine, isoleucine, valine, and methionine). Related ribozymes exhibited shared preferences for substrates, indicating that adoption of additional amino acids by existing ribozymes would itself lead to error minimization. Furthermore, ribozyme activity was positively correlated with specificity, indicating that selection for increased activity would also lead to increased specificity. These results demonstrate that by-products of ribozyme evolution could lead to adaptive value in specificity and error tolerance.
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Affiliation(s)
- Evan Janzen
- Program in Biomolecular Science and Engineering, University of California, Santa Barbara, CA, 93106, USA.,Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Yuning Shen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA.,Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Alberto Vázquez-Salazar
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Ziwei Liu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Celia Blanco
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Josh Kenchel
- Program in Biomolecular Science and Engineering, University of California, Santa Barbara, CA, 93106, USA.,Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA.,Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Irene A Chen
- Program in Biomolecular Science and Engineering, University of California, Santa Barbara, CA, 93106, USA. .,Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA. .,Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA.
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4
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Weiss Z, DasGupta S. REVERSE: a user-friendly web server for analyzing next-generation sequencing data from in vitro selection/evolution experiments. Nucleic Acids Res 2022; 50:W639-W650. [PMID: 35699225 PMCID: PMC9252737 DOI: 10.1093/nar/gkac508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/22/2022] [Accepted: 05/27/2022] [Indexed: 11/14/2022] Open
Abstract
Next-generation sequencing (NGS) enables the identification of functional nucleic acid sequences from in vitro selection/evolution experiments and illuminates the evolutionary process at single-nucleotide resolution. However, analyzing the vast output from NGS can be daunting, especially with limited programming skills. We developed REVERSE (Rapid EValuation of Experimental RNA Selection/Evolution) (https://www.reverseserver.org/), a web server that implements an integrated computational pipeline through a graphical user interface, which performs both pre-processing and detailed sequence level analyses within minutes. Raw FASTQ files are quality-filtered, dereplicated, and trimmed before being analyzed by either of two pipelines. The first pipeline counts, sorts, and tracks enrichment of unique sequences and user-defined sequence motifs. It also identifies mutational intermediates present in the sequence data that connect two input sequences. The second pipeline sorts similar sequences into clusters and tracks enrichment of peak sequences. It also performs nucleotide conservation analysis on the cluster of choice and generates a consensus sequence. Both pipelines generate downloadable spreadsheets and high-resolution figures. Collectively, REVERSE is a one-stop solution for the rapid analysis of NGS data obtained from in vitro selection/evolution experiments that obviates the need for computational expertise.
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Affiliation(s)
- Zoe Weiss
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Saurja DasGupta
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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5
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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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6
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PacBio sequencing output increased through uniform and directional fivefold concatenation. Sci Rep 2021; 11:18065. [PMID: 34508117 PMCID: PMC8433307 DOI: 10.1038/s41598-021-96829-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/17/2021] [Indexed: 12/20/2022] Open
Abstract
Advances in sequencing technology have allowed researchers to sequence DNA with greater ease and at decreasing costs. Main developments have focused on either sequencing many short sequences or fewer large sequences. Methods for sequencing mid-sized sequences of 600-5,000 bp are currently less efficient. For example, the PacBio Sequel I system yields ~ 100,000-300,000 reads with an accuracy per base pair of 90-99%. We sought to sequence several DNA populations of ~ 870 bp in length with a sequencing accuracy of 99% and to the greatest depth possible. We optimised a simple, robust method to concatenate genes of ~ 870 bp five times and then sequenced the resulting DNA of ~ 5,000 bp by PacBioSMRT long-read sequencing. Our method improved upon previously published concatenation attempts, leading to a greater sequencing depth, high-quality reads and limited sample preparation at little expense. We applied this efficient concatenation protocol to sequence nine DNA populations from a protein engineering study. The improved method is accompanied by a simple and user-friendly analysis pipeline, DeCatCounter, to sequence medium-length sequences efficiently at one-fifth of the cost.
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7
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Kamalinia G, Grindel BJ, Takahashi TT, Millward SW, Roberts RW. Directing evolution of novel ligands by mRNA display. Chem Soc Rev 2021; 50:9055-9103. [PMID: 34165126 PMCID: PMC8725378 DOI: 10.1039/d1cs00160d] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
mRNA display is a powerful biological display platform for the directed evolution of proteins and peptides. mRNA display libraries covalently link the displayed peptide or protein (phenotype) with the encoding genetic information (genotype) through the biochemical activity of the small molecule puromycin. Selection for peptide/protein function is followed by amplification of the linked genetic material and generation of a library enriched in functional sequences. Iterative selection cycles are then performed until the desired level of function is achieved, at which time the identity of candidate peptides can be obtained by sequencing the genetic material. The purpose of this review is to discuss the development of mRNA display technology since its inception in 1997 and to comprehensively review its use in the selection of novel peptides and proteins. We begin with an overview of the biochemical mechanism of mRNA display and its variants with a particular focus on its advantages and disadvantages relative to other biological display technologies. We then discuss the importance of scaffold choice in mRNA display selections and review the results of selection experiments with biological (e.g., fibronectin) and linear peptide library architectures. We then explore recent progress in the development of "drug-like" peptides by mRNA display through the post-translational covalent macrocyclization and incorporation of non-proteogenic functionalities. We conclude with an examination of enabling technologies that increase the speed of selection experiments, enhance the information obtained in post-selection sequence analysis, and facilitate high-throughput characterization of lead compounds. We hope to provide the reader with a comprehensive view of current state and future trajectory of mRNA display and its broad utility as a peptide and protein design tool.
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Affiliation(s)
- Golnaz Kamalinia
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA.
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8
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Shen Y, Pressman A, Janzen E, Chen IA. Kinetic sequencing (k-Seq) as a massively parallel assay for ribozyme kinetics: utility and critical parameters. Nucleic Acids Res 2021; 49:e67. [PMID: 33772580 PMCID: PMC8559535 DOI: 10.1093/nar/gkab199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/15/2021] [Accepted: 03/13/2021] [Indexed: 12/26/2022] Open
Abstract
Characterizing genotype-phenotype relationships of biomolecules (e.g. ribozymes) requires accurate ways to measure activity for a large set of molecules. Kinetic measurement using high-throughput sequencing (e.g. k-Seq) is an emerging assay applicable in various domains that potentially scales up measurement throughput to over 106 unique nucleic acid sequences. However, maximizing the return of such assays requires understanding the technical challenges introduced by sequence heterogeneity and DNA sequencing. We characterized the k-Seq method in terms of model identifiability, effects of sequencing error, accuracy and precision using simulated datasets and experimental data from a variant pool constructed from previously identified ribozymes. Relative abundance, kinetic coefficients, and measurement noise were found to affect the measurement of each sequence. We introduced bootstrapping to robustly quantify the uncertainty in estimating model parameters and proposed interpretable metrics to quantify model identifiability. These efforts enabled the rigorous reporting of data quality for individual sequences in k-Seq experiments. Here we present detailed protocols, define critical experimental factors, and identify general guidelines to maximize the number of sequences and their measurement accuracy from k-Seq data. Analogous practices could be applied to improve the rigor of other sequencing-based assays.
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Affiliation(s)
- Yuning Shen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Abe Pressman
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Evan Janzen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.,Program in Biomolecular Sciences and Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Irene A Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.,Program in Biomolecular Sciences and Engineering, University of California, Santa Barbara, CA 93106, USA.,Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
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9
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Lai YC, Liu Z, Chen IA. Encapsulation of ribozymes inside model protocells leads to faster evolutionary adaptation. Proc Natl Acad Sci U S A 2021; 118:e2025054118. [PMID: 34001592 PMCID: PMC8166191 DOI: 10.1073/pnas.2025054118] [Citation(s) in RCA: 15] [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: 02/07/2023] Open
Abstract
Functional biomolecules, such as RNA, encapsulated inside a protocellular membrane are believed to have comprised a very early, critical stage in the evolution of life, since membrane vesicles allow selective permeability and create a unit of selection enabling cooperative phenotypes. The biophysical environment inside a protocell would differ fundamentally from bulk solution due to the microscopic confinement. However, the effect of the encapsulated environment on ribozyme evolution has not been previously studied experimentally. Here, we examine the effect of encapsulation inside model protocells on the self-aminoacylation activity of tens of thousands of RNA sequences using a high-throughput sequencing assay. We find that encapsulation of these ribozymes generally increases their activity, giving encapsulated sequences an advantage over nonencapsulated sequences in an amphiphile-rich environment. In addition, highly active ribozymes benefit disproportionately more from encapsulation. The asymmetry in fitness gain broadens the distribution of fitness in the system. Consistent with Fisher's fundamental theorem of natural selection, encapsulation therefore leads to faster adaptation when the RNAs are encapsulated inside a protocell during in vitro selection. Thus, protocells would not only provide a compartmentalization function but also promote activity and evolutionary adaptation during the origin of life.
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Affiliation(s)
- Yei-Chen Lai
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - Ziwei Liu
- Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
| | - Irene A Chen
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095;
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
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10
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Zakrevsky P, Calkins E, Kao YL, Singh G, Keleshian VL, Baudrey S, Jaeger L. In vitro selected GUAA tetraloop-binding receptors with structural plasticity and evolvability towards natural RNA structural modules. Nucleic Acids Res 2021; 49:2289-2305. [PMID: 33524109 PMCID: PMC7913685 DOI: 10.1093/nar/gkab021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/05/2021] [Accepted: 01/26/2021] [Indexed: 11/24/2022] Open
Abstract
GNRA tetraloop-binding receptor interactions are key components in the macromolecular assembly of a variety of functional RNAs. In nature, there is an apparent bias for GAAA/11nt receptor and GYRA/helix interactions, with the former interaction being thermodynamically more stable than the latter. While past in vitro selections allowed isolation of novel GGAA and GUGA receptors, we report herein an in vitro selection that revealed several novel classes of specific GUAA receptors with binding affinities comparable to those from natural GAAA/11nt interactions. These GUAA receptors have structural homology with double-locked bulge RNA modules naturally occurring in ribosomal RNAs. They display mutational robustness that enables exploration of the sequence/phenotypic space associated to GNRA/receptor interactions through epistasis. Their thermodynamic self-assembly fitness landscape is characterized by a rugged neutral network with possible evolutionary trajectories toward natural GNRA/receptor interactions. High throughput sequencing analysis revealed synergetic mutations located away from the tertiary interactions that positively contribute to assembly fitness. Our study suggests that the repertoire of GNRA/receptor interactions is much larger than initially thought from the analysis of natural stable RNA molecules and also provides clues for their evolution towards natural GNRA/receptors.
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Affiliation(s)
- Paul Zakrevsky
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Erin Calkins
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Yi-Ling Kao
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Gurkeerat Singh
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Vasken L Keleshian
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Stephanie Baudrey
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
| | - Luc Jaeger
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106-9510, USA
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