1
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Sun L, Ma X, Zhang B, Qin Y, Ma J, Du Y, Chen T. From polymerase engineering to semi-synthetic life: artificial expansion of the central dogma. RSC Chem Biol 2022; 3:1173-1197. [PMID: 36320892 PMCID: PMC9533422 DOI: 10.1039/d2cb00116k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/08/2022] [Indexed: 11/21/2022] Open
Abstract
Nucleic acids have been extensively modified in different moieties to expand the scope of genetic materials in the past few decades. While the development of unnatural base pairs (UBPs) has expanded the genetic information capacity of nucleic acids, the production of synthetic alternatives of DNA and RNA has increased the types of genetic information carriers and introduced novel properties and functionalities into nucleic acids. Moreover, the efforts of tailoring DNA polymerases (DNAPs) and RNA polymerases (RNAPs) to be efficient unnatural nucleic acid polymerases have enabled broad application of these unnatural nucleic acids, ranging from production of stable aptamers to evolution of novel catalysts. The introduction of unnatural nucleic acids into living organisms has also started expanding the central dogma in vivo. In this article, we first summarize the development of unnatural nucleic acids with modifications or alterations in different moieties. The strategies for engineering DNAPs and RNAPs are then extensively reviewed, followed by summarization of predominant polymerase mutants with good activities for synthesizing, reverse transcribing, or even amplifying unnatural nucleic acids. Some recent application examples of unnatural nucleic acids with their polymerases are then introduced. At the end, the approaches of introducing UBPs and synthetic genetic polymers into living organisms for the creation of semi-synthetic organisms are reviewed and discussed.
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Affiliation(s)
- Leping Sun
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Xingyun Ma
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Binliang Zhang
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Yanjia Qin
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Jiezhao Ma
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Yuhui Du
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
| | - Tingjian Chen
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology 510006 Guangzhou China
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2
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Song Z, Liang Y, Yang J. Nanopore Detection Assisted DNA Information Processing. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12183135. [PMID: 36144924 PMCID: PMC9504103 DOI: 10.3390/nano12183135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/04/2022] [Accepted: 09/06/2022] [Indexed: 05/27/2023]
Abstract
The deoxyribonucleotide (DNA) molecule is a stable carrier for large amounts of genetic information and provides an ideal storage medium for next-generation information processing technologies. Technologies that process DNA information, representing a cross-disciplinary integration of biology and computer techniques, have become attractive substitutes for technologies that process electronic information alone. The detailed applications of DNA technologies can be divided into three components: storage, computing, and self-assembly. The quality of DNA information processing relies on the accuracy of DNA reading. Nanopore detection allows researchers to accurately sequence nucleotides and is thus widely used to read DNA. In this paper, we introduce the principles and development history of nanopore detection and conduct a systematic review of recent developments and specific applications in DNA information processing involving nanopore detection and nanopore-based storage. We also discuss the potential of artificial intelligence in nanopore detection and DNA information processing. This work not only provides new avenues for future nanopore detection development, but also offers a foundation for the construction of more advanced DNA information processing technologies.
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Affiliation(s)
- Zichen Song
- School of Control and Computer Engineering, North China Electric Power University, Beijing 102206, China
| | - Yuan Liang
- Department of Computer Science and Technology, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China
| | - Jing Yang
- School of Control and Computer Engineering, North China Electric Power University, Beijing 102206, China
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3
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Directed Evolution Methods for Enzyme Engineering. Molecules 2021; 26:molecules26185599. [PMID: 34577070 PMCID: PMC8470892 DOI: 10.3390/molecules26185599] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 11/22/2022] Open
Abstract
Enzymes underpin the processes required for most biotransformations. However, natural enzymes are often not optimal for biotechnological uses and must be engineered for improved activity, specificity and stability. A rich and growing variety of wet-lab methods have been developed by researchers over decades to accomplish this goal. In this review such methods and their specific attributes are examined.
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4
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Song P, Zhang R, He C, Chen T. Transcription, Reverse Transcription, and Amplification of Backbone-Modified Nucleic Acids with Laboratory-Evolved Thermophilic DNA Polymerases. Curr Protoc 2021; 1:e188. [PMID: 34232574 DOI: 10.1002/cpz1.188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Backbone-modified nucleic acids are usually more stable enzymatically than their natural counterparts, enabling their broad application as potential diagnostic or therapeutic agents. Moreover, the development of nucleic acids with unnatural backbones has expanded the pool of genetic information carriers and paved the way toward synthetic xenobiology. However, synthesizing these molecules remains very challenging due to the requirement for harsh reaction conditions and the low coupling efficiency during their traditional solid-phase synthesis. Although enzymatic synthesis provides an attractive alternative that also allows the replication and artificial evolution of these molecules, it is crucially dependent on the availability of polymerases capable of synthesizing these backbone-modified nucleotides. Previously, a series of thermostable polymerases that can efficiently synthesize or even amplify backbone-modified DNA or RNA have been evolved through a polymerase evolution method based on phage display. Herein we summarize protocols to use these evolved polymerase mutants to transcribe, reverse transcribe, and PCR amplify backbone-modified nucleic acids. We also outline the polymerase chain transcription method, developed later for the rapid production of RNA or backbone-modified RNA with one of these evolved polymerases, SFM4-3. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Transcription/synthesis of modified DNA/RNA from DNA templates with evolved polymerases SFM4-3 or SFM4-6 Basic Protocol 2: Reverse transcription of modified DNA/RNA with evolved polymerase SFM4-9 Basic Protocol 3: PCR amplification of modified DNA with evolved polymerase SFM4-3 Basic Protocol 4: Polymerase chain transcription for the production of RNA/modified RNA oligonucleotides with evolved polymerase SFM4-3.
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Affiliation(s)
- Ping Song
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, P. R. China
| | - Rujie Zhang
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, P. R. China
| | - Chuanping He
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, P. R. China
| | - Tingjian Chen
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, P. R. China
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5
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Ouaray Z, Benner SA, Georgiadis MM, Richards NGJ. Building better polymerases: Engineering the replication of expanded genetic alphabets. J Biol Chem 2020; 295:17046-17059. [PMID: 33004440 PMCID: PMC7863901 DOI: 10.1074/jbc.rev120.013745] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
DNA polymerases are today used throughout scientific research, biotechnology, and medicine, in part for their ability to interact with unnatural forms of DNA created by synthetic biologists. Here especially, natural DNA polymerases often do not have the "performance specifications" needed for transformative technologies. This creates a need for science-guided rational (or semi-rational) engineering to identify variants that replicate unnatural base pairs (UBPs), unnatural backbones, tags, or other evolutionarily novel features of unnatural DNA. In this review, we provide a brief overview of the chemistry and properties of replicative DNA polymerases and their evolved variants, focusing on the Klenow fragment of Taq DNA polymerase (Klentaq). We describe comparative structural, enzymatic, and molecular dynamics studies of WT and Klentaq variants, complexed with natural or noncanonical substrates. Combining these methods provides insight into how specific amino acid substitutions distant from the active site in a Klentaq DNA polymerase variant (ZP Klentaq) contribute to its ability to replicate UBPs with improved efficiency compared with Klentaq. This approach can therefore serve to guide any future rational engineering of replicative DNA polymerases.
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Affiliation(s)
- Zahra Ouaray
- School of Chemistry, Cardiff University, Park Place, Cardiff, United Kingdom
| | - Steven A Benner
- Foundation for Applied Molecular Evolution, Alachua, Florida, USA
| | - Millie M Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
| | - Nigel G J Richards
- School of Chemistry, Cardiff University, Park Place, Cardiff, United Kingdom; Foundation for Applied Molecular Evolution, Alachua, Florida, USA.
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6
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Duffy K, Arangundy-Franklin S, Holliger P. Modified nucleic acids: replication, evolution, and next-generation therapeutics. BMC Biol 2020; 18:112. [PMID: 32878624 PMCID: PMC7469316 DOI: 10.1186/s12915-020-00803-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Modified nucleic acids, also called xeno nucleic acids (XNAs), offer a variety of advantages for biotechnological applications and address some of the limitations of first-generation nucleic acid therapeutics. Indeed, several therapeutics based on modified nucleic acids have recently been approved and many more are under clinical evaluation. XNAs can provide increased biostability and furthermore are now increasingly amenable to in vitro evolution, accelerating lead discovery. Here, we review the most recent discoveries in this dynamic field with a focus on progress in the enzymatic replication and functional exploration of XNAs.
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Affiliation(s)
- Karen Duffy
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | | | - Philipp Holliger
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
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7
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Chung ME, Goroncy K, Kolesnikova A, Schönauer D, Schwaneberg U. Display of functional nucleic acid polymerase on Escherichia coli surface and its application in directed polymerase evolution. Biotechnol Bioeng 2020; 117:3699-3711. [PMID: 32827316 DOI: 10.1002/bit.27542] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/30/2020] [Accepted: 08/09/2020] [Indexed: 12/29/2022]
Abstract
We report a first of its kind functional cell surface display of nucleic acid polymerase and its directed evolution to efficiently incorporate 2'-O-methyl nucleotide triphosphates (2'-OMe-NTPs). In the development of polymerase cell surface display, two autotransporter proteins (Escherichia coli adhesin involved in diffuse adherence and Pseudomonas aeruginosa esterase A [EstA]) were employed to transport and anchor the 68-kDa Klenow fragment (KF) of E. coli DNA polymerase I on the surface of E. coli. The localization and function of the displayed KF were verified by analysis of cell outer membrane fractions, immunostaining, and fluorometric detection of synthesized DNA products. The EstA cell surface display system was applied to evolve KF for the incorporation of 2'-OMe-NTPs and a KF variant with a 50.7-fold increased ability to successively incorporate 2'-OMe-NTPs was discovered. Expanding the scope of cell-surface displayable proteins to the realm of polymerases provides a novel screening tool for tailoring polymerases to diverse application demands in a polymerase chain reaction and sequencing-based biotechnological and medical applications. Especially, cell surface display enables novel polymerase screening strategies in which the heat-lysis step is bypassed and thus allows the screening of mesophilic polymerases with broad application potentials ranging from diagnostics and DNA sequencing to replication of synthetic genetic polymers.
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Affiliation(s)
- Mu-En Chung
- SeSaM-Biotech GmbH, Aachen, Germany.,Lehrstuhl für Biotechnologie, RWTH Aachen University, Aachen, Germany
| | | | | | | | - Ulrich Schwaneberg
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Aachen, Germany.,DWI-Leibniz-Institute for Interactive Materials, Aachen, Germany
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8
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Abstract
The chemical or prebiotic evolution referred also to as pre-Darwinian evolution describes chemical reactions up to the origin of a self-replicating system that was capable of Darwinian evolution. These chemical processes took place on Earth between about 3.7 and 4.5 billion years ago when cellular life came into being. The pre-Darwinian chemical evolution usually assumes hereditary elements, but does not regard them as self-organizing processes. Physical and chemical self-organization led to uninterrupted pre-Darwinian and Darwinian evolution. Thus, it is not justified to distinguish between different types of evolution. From the many possible solutions, evolution selected among those reactions that generated catalytic networks incorporating chemical sequence information and under gradually changing circumstances produced a reproducible and stable living system that adapted to these conditions. Major issues in this review involve prebiotic reactions leading to genetic evolution involving (1) abiotic sources of components of ribonucleotides and xenobiotic nucleotides, (2) formation of prebiotic RNA, (3) development of genetic RNA from random-sequence noncoding RNA, (4) transition from RNA World to DNA Empire, (5) the role of oxygenic photosynthesis in genetic transitions, and (6) hierarchical arrangement of processes involved in the optimized genetic system.
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Affiliation(s)
- Gaspar Banfalvi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
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9
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Engineering-driven biological insights into DNA polymerase mechanism. Curr Opin Biotechnol 2018; 60:9-16. [PMID: 30502514 DOI: 10.1016/j.copbio.2018.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/13/2018] [Indexed: 12/11/2022]
Abstract
DNA-dependent DNA polymerases have been extensively studied for over 60 years and lie at the core of multiple biotechnological and diagnostic applications. Nevertheless, these complex molecular machines remain only partially understood. Here we present some evidence on how polymerase engineering for the synthesis and replication of xenobiotic nucleic acids (XNAs) have improved our understanding of these enzymes and how that can be used to gain further insight into their mechanism. Better understanding of the mechanisms of DNA polymerases can accelerate their engineering and we highlight how it is now feasible to use structure-based and function-based approaches to systematically and iteratively develop XNA polymerases for increasingly divergent chemistries.
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10
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Saha R, Verbanic S, Chen IA. Lipid vesicles chaperone an encapsulated RNA aptamer. Nat Commun 2018; 9:2313. [PMID: 29899431 PMCID: PMC5998061 DOI: 10.1038/s41467-018-04783-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 05/22/2018] [Indexed: 01/08/2023] Open
Abstract
The organization of molecules into cells is believed to have been critical for the emergence of living systems. Early protocells likely consisted of RNA functioning inside vesicles made of simple lipids. However, little is known about how encapsulation would affect the activity and folding of RNA. Here we find that confinement of the malachite green RNA aptamer inside fatty acid vesicles increases binding affinity and locally stabilizes the bound conformation of the RNA. The vesicle effectively ‘chaperones’ the aptamer, consistent with an excluded volume mechanism due to confinement. Protocellular organization thereby leads to a direct benefit for the RNA. Coupled with previously described mechanisms by which encapsulated RNA aids membrane growth, this effect illustrates how the membrane and RNA might cooperate for mutual benefit. Encapsulation could thus increase RNA fitness and the likelihood that functional sequences would emerge during the origin of life. So far little is known about how encapsulation affects the activity and folding of RNA, which is of interest for understanding the origin of cellular life. Here the authors show that encapsulation of functional RNA in vesicles increases RNA activity and improves RNA folding through a biophysical confinement effect.
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Affiliation(s)
- Ranajay Saha
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Samuel Verbanic
- 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.
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11
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Taylor AI, Holliger P. Selecting Fully-Modified XNA Aptamers Using Synthetic Genetics. ACTA ACUST UNITED AC 2018; 10:e44. [PMID: 29927117 DOI: 10.1002/cpch.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This unit describes the application of "synthetic genetics," i.e., the replication of xeno nucleic acids (XNAs), artificial analogs of DNA and RNA bearing alternative backbone or sugar congeners, to the directed evolution of synthetic oligonucleotide ligands (XNA aptamers) specific for target proteins or nucleic acid motifs, using a cross-chemistry selective exponential enrichment (X-SELEX) approach. Protocols are described for synthesis of diverse-sequence XNA repertoires (typically 1014 molecules) using DNA templates, isolation and panning for functional XNA sequences using targets immobilized on solid phase or gel shift induced by target binding in solution, and XNA reverse transcription to allow cDNA amplification or sequencing. The method may be generally applied to select fully-modified XNA aptamers specific for a wide range of target molecules. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Alexander I Taylor
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Philipp Holliger
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
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12
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Abil Z, Ellington AD. Compartmentalized Self-Replication for Evolution of a DNA Polymerase. ACTA ACUST UNITED AC 2018; 10:1-17. [DOI: 10.1002/cpch.34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Zhanar Abil
- Center for Systems and Synthetic Biology University of Texas at Austin; Austin Texas
| | - Andrew D. Ellington
- Center for Systems and Synthetic Biology University of Texas at Austin; Austin Texas
- Institute for Cellular and Molecular Biology, Department of Chemistry and Biochemistry, University of Texas at Austin; Austin Texas
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13
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Nikoomanzar A, Dunn MR, Chaput JC. Engineered Polymerases with Altered Substrate Specificity: Expression and Purification. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/cpnc.33] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Ali Nikoomanzar
- Department of Pharmaceutical Sciences. University of California Irvine California
| | - Matthew R. Dunn
- Department of Pharmaceutical Sciences. University of California Irvine California
| | - John C. Chaput
- Department of Pharmaceutical Sciences. University of California Irvine California
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14
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Houlihan G, Arangundy-Franklin S, Holliger P. Engineering and application of polymerases for synthetic genetics. Curr Opin Biotechnol 2017; 48:168-179. [PMID: 28601700 DOI: 10.1016/j.copbio.2017.04.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 11/26/2022]
Abstract
Organic chemistry has systematically probed the chemical determinants of function in nucleic acids by variation to the nucleobase, sugar ring and backbone moieties to build synthetic genetic polymers. Concomitantly, protein engineering has advanced to allow the discovery of polymerases capable of utilizing modified nucleotide analogs. A conjunction of these two lines of investigation in nucleotide chemistry and molecular biology has given rise to a new field of synthetic genetics dedicated to the exploration of the capacity of these novel, synthetic nucleic acids for the storage and propagation of genetic information, for evolution and for crosstalk, that is, information exchange with the natural genetic system. Here we summarize recent progress in synthetic genetics, specifically in the design of novel unnatural basepairs to expand the genetic alphabet as well as progress in engineering polymerases capable of templated synthesis, reverse transcription and evolution of synthetic genetic polymers.
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Affiliation(s)
- Gillian Houlihan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | | | - Philipp Holliger
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK.
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15
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Houlihan G, Arangundy-Franklin S, Holliger P. Exploring the Chemistry of Genetic Information Storage and Propagation through Polymerase Engineering. Acc Chem Res 2017; 50:1079-1087. [PMID: 28383245 PMCID: PMC5406124 DOI: 10.1021/acs.accounts.7b00056] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Nucleic
acids are a distinct form of sequence-defined biopolymer.
What sets them apart from other biopolymers such as polypeptides or
polysaccharides is their unique capacity to encode, store, and propagate
genetic information (molecular heredity). In nature, just two closely
related nucleic acids, DNA and RNA, function as repositories and carriers
of genetic information. They therefore are the molecular embodiment
of biological information. This naturally leads to questions regarding
the degree of variation from this seemingly ideal “Goldilocks”
chemistry that would still be compatible with the fundamental property
of molecular heredity. To address this question, chemists have
created a panoply of synthetic
nucleic acids comprising unnatural sugar ring congeners, backbone
linkages, and nucleobases in order to establish the molecular parameters
for encoding genetic information and its emergence at the origin of
life. A deeper analysis of the potential of these synthetic genetic
polymers for molecular heredity requires a means of replication and
a determination of the fidelity of information transfer. While non-enzymatic
synthesis is an increasingly powerful method, it currently remains
restricted to short polymers. Here we discuss efforts toward establishing
enzymatic synthesis, replication, and evolution of synthetic genetic
polymers through the engineering of polymerase enzymes found in nature. To endow natural polymerases with the ability to efficiently utilize
non-cognate nucleotide substrates, novel strategies for the screening
and directed evolution of polymerase function have been realized.
High throughput plate-based screens, phage display, and water-in-oil
emulsion technology based methods have yielded a number of engineered
polymerases, some of which can synthesize and reverse transcribe synthetic
genetic polymers with good efficiency and fidelity. The inception
of such polymerases demonstrates that, at a basic
level at least, molecular heredity is not restricted to the natural
nucleic acids DNA and RNA, but may be found in a large (if finite)
number of synthetic genetic polymers. And it has opened up these novel
sequence spaces for investigation. Although largely unexplored, first
tentative forays have yielded ligands (aptamers) against a range of
targets and several catalysts elaborated in a range of different chemistries.
Finally, taking the lead from established DNA designs, simple polyhedron
nanostructures have been described. We anticipate that further
progress in this area will expand the
range of synthetic genetic polymers that can be synthesized, replicated,
and evolved providing access to a rich sequence, structure, and phenotypic
space. “Synthetic genetics”, that is, the exploration
of these spaces, will illuminate the chemical parameter range for
en- and decoding information, 3D folding, and catalysis and yield
novel ligands, catalysts, and nanostructures and devices for applications
in biotechnology and medicine.
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Affiliation(s)
- Gillian Houlihan
- MRC Laboratory of Molecular Biology, Francis Crick
Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
| | | | - Philipp Holliger
- MRC Laboratory of Molecular Biology, Francis Crick
Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, U.K
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16
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Povilaitis T, Alzbutas G, Sukackaite R, Siurkus J, Skirgaila R. In vitroevolution of phi29 DNA polymerase using isothermal compartmentalized self replication technique. Protein Eng Des Sel 2016; 29:617-628. [DOI: 10.1093/protein/gzw052] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/18/2016] [Accepted: 09/05/2016] [Indexed: 02/06/2023] Open
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17
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Kong D, Yeung W, Hili R. Generation of Synthetic Copolymer Libraries by Combinatorial Assembly on Nucleic Acid Templates. ACS COMBINATORIAL SCIENCE 2016; 18:355-70. [PMID: 27275512 DOI: 10.1021/acscombsci.6b00059] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recent advances in nucleic acid-templated copolymerization have expanded the scope of sequence-controlled synthetic copolymers beyond the molecular architectures witnessed in nature. This has enabled the power of molecular evolution to be applied to synthetic copolymer libraries to evolve molecular function ranging from molecular recognition to catalysis. This Review seeks to summarize different approaches available to generate sequence-defined monodispersed synthetic copolymer libraries using nucleic acid-templated polymerization. Key concepts and principles governing nucleic acid-templated polymerization, as well as the fidelity of various copolymerization technologies, will be described. The Review will focus on methods that enable the combinatorial generation of copolymer libraries and their molecular evolution for desired function.
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Affiliation(s)
- Dehui Kong
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
| | - Wayland Yeung
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
| | - Ryan Hili
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
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18
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Meek KN, Rangel AE, Heemstra JM. Enhancing aptamer function and stability via in vitro selection using modified nucleic acids. Methods 2016; 106:29-36. [PMID: 27012179 DOI: 10.1016/j.ymeth.2016.03.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 11/29/2022] Open
Abstract
Nucleic acid aptamers have emerged as a promising alternative to antibodies for use as recognition elements in therapeutics, bioimaging, and analytical applications. A key benefit that aptamers possess relative to antibodies is their ability to be chemically synthesized. This advantage, coupled with the broad range of modified nucleotide building blocks that can be constructed using chemical synthesis, has enabled the discovery and development of modified aptamers having extraordinary affinity, specificity, and biostability. Early efforts to generate modified aptamers focused on selection of a native DNA or RNA aptamer, followed by post-selection trial-and-error testing of modifications. However, recent advances in polymerase engineering and templated nucleic acid synthesis have enabled the direct selection of aptamers having modified backbones and nucleobases. This review will discuss these technological advances and highlight the improvements in aptamer function that have been realized through in vitro selection of non-natural nucleic acids.
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Affiliation(s)
- Kirsten N Meek
- Department of Chemistry and the Center for Cell and Genome Science, University of Utah, 315 S 1400 E, Salt Lake City, UT 84112, United States
| | - Alexandra E Rangel
- Department of Chemistry and the Center for Cell and Genome Science, University of Utah, 315 S 1400 E, Salt Lake City, UT 84112, United States
| | - Jennifer M Heemstra
- Department of Chemistry and the Center for Cell and Genome Science, University of Utah, 315 S 1400 E, Salt Lake City, UT 84112, United States.
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Delespaul W, Peeters Y, Herdewijn P, Robben J. A novel helper phage for HaloTag-mediated co-display of enzyme and substrate on phage. Biochem Biophys Res Commun 2015; 460:245-9. [PMID: 25772618 DOI: 10.1016/j.bbrc.2015.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
Phage display is an established technique for the molecular evolution of peptides and proteins. For the selection of enzymes based on catalytic activity however, simultaneous coupling of an enzyme and its substrate to the phage surface is required. To facilitate this process of co-display, we developed a new helper phage displaying HaloTag, a modified haloalkane dehalogenase that binds specifically and covalently to functionalized haloalkane ligands. The display of functional HaloTag was demonstrated by capture on streptavidin-coated magnetic beads, after coupling a biotinylated haloalkane ligand, or after on-phage extension of a DNA oligonucleotide primer with a biotinylated nucleotide by phi29 DNA polymerase. We also achieved co-display of HaloTag and phi29 DNA polymerase, thereby opening perspectives for the molecular evolution of this enzyme (and others) towards new substrate specificities.
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Affiliation(s)
- Wouter Delespaul
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, B-3001 Heverlee, Belgium.
| | - Yves Peeters
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, B-3001 Heverlee, Belgium.
| | - Piet Herdewijn
- Rega Institute for Medicinal Research, KU Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
| | - Johan Robben
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, B-3001 Heverlee, Belgium.
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