1
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Dutta S, Srivatsan SG. Enzymatic Functionalization of RNA Oligonucleotides by Terminal Uridylyl Transferase Using Fluorescent and Clickable Nucleotide Analogs. Chem Asian J 2024; 19:e202400475. [PMID: 38949615 DOI: 10.1002/asia.202400475] [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: 04/26/2024] [Revised: 06/27/2024] [Accepted: 07/01/2024] [Indexed: 07/02/2024]
Abstract
We report a systematic study on controlling the enzyme activity of a terminal uridylyl transferase (TUTase) called SpCID1, which provides methods to effect site-specific incorporation of a single modified nucleotide analog at the 3'-end of an RNA oligonucleotide (ON). Responsive heterocycle-modified fluorescent UTP probes that are useful in analyzing non-canonical nucleic acid structures and azide- and alkyne-modified UTP analogs that are compatible for chemoenzymatic functionalization were used as study systems. In the first strategy, we balanced the concentration of essential metal ion cofactors (Mg2+ and Mn2+ ions) to restrict the processivity of the enzyme, which gave a very good control on the incorporation of clickable nucleotide analogs. In the second approach, borate that complexes with 2' and 3' oxygen atoms of a ribose sugar was used as a reversibly binding chelator to block repeated addition of nucleotide analogs. Notably, in the presence of heterocycle-modified fluorescent UTPs, we obtained single-nucleotide incorporated RNA products in reasonable yields, while with clickable nucleotides yields were very good. Further, 3'-end azide- and alkyne-labeled RNA ONs were post-enzymatically functionalized by CuAAC and SPAAC reactions with fluorescent probes. These strategies broaden the scope of TUTase in site-specifically installing modifications of different types onto RNA for various applications.
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Affiliation(s)
- Swagata Dutta
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune Dr. Homi Bhabha Road, Pune, 411008, India
| | - Seergazhi G Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune Dr. Homi Bhabha Road, Pune, 411008, India
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2
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Laatri S, El Khayari S, Qriouet Z. Exploring the molecular aspect and updating evolutionary approaches to the DNA polymerase enzymes for biotechnological needs: A comprehensive review. Int J Biol Macromol 2024; 276:133924. [PMID: 39033894 DOI: 10.1016/j.ijbiomac.2024.133924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 07/07/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024]
Abstract
DNA polymerases are essential enzymes that play a key role in living organisms, as they participate in the synthesis and maintenance of the DNA molecule. The intrinsic properties of these enzymes have been widely observed and studied to understand their functions, activities, and behavior, which has allowed their natural power in DNA synthesis to be exploited in modern biotechnology, to the point of making them true pillars of the field. In this context, the laboratory evolution of these enzymes, either by directed evolution or rational design, has led to the generation of a wide range of new DNA polymerases with novel properties, suitable for a variety of biotechnological needs. In this review, we examine DNA polymerases at the molecular level, their biotechnological use, and their evolutionary methods in relation to the novel properties sought, providing a chronological selection of evolved DNA polymerases cited in the literature that we consider to be of great interest. To our knowledge, this work is the first to bring together the molecular, functional and evolutionary aspects of the DNA polymerase enzyme. We believe it will be of great interest to researchers whose aim is to produce new lines of evolved DNA polymerases.
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Affiliation(s)
- Said Laatri
- Microbiology and Molecular Biology Laboratory, Faculty of Sciences, Mohammed V-Souissi University, Rabat 10100, Morocco.
| | | | - Zidane Qriouet
- Pharmacology and Toxicology Laboratory, Faculty of Medicine and Pharmacy, Mohammed V-Souissi University, Rabat 10100, Morocco
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3
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Sett A, Gadewar M, Babu MA, Panja A, Sachdeva P, Almutary AG, Upadhye V, Jha SK, Jha NK. Orchestration and theranostic applications of synthetic genome with Hachimoji bases/building blocks. Chem Biol Drug Des 2024; 103:e14378. [PMID: 38230795 DOI: 10.1111/cbdd.14378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 01/18/2024]
Abstract
Synthetic genomics is a novel field of chemical biology where the chemically modified genetic alphabets have been considered in central dogma of life. Tweaking of chemical compositions of natural nucleotide bases could be developed as novel building blocks of DNA/RNA. The modified bases (dP, dZ, dS, and dB etc.) have been demonstrated to be adaptable for replication, transcription and follow Darwinism law of evolution. With advancement of chemical biology especially nucleotide chemistry, synthetic genetic codes have been discovered and Hachimoji nucleotides are the most important and significant one among them. These additional nucleotide bases can form orthogonal base-pairing, and also follow Darwinian evolution and other structural features. In the Hachimoji base pairing, synthetic building blocks are formed using eight modified nucleotide (DNA/RNA) letters (hence the name "Hachimoji"). Their structural conformations, like polyelectrolyte backbones and stereo-regular building blocks favor thermodynamic stability and confirm Schrodinger aperiodic crystal. From the structural genomics aspect, these synthetic bases could be incorporated into the central dogma of life. Researchers have shown Hachimoji building blocks were transcribed to its RNA counterpart as a functional fluorescent Hachimoji aptamer. Apart from several unnatural nucleotide base pairs maneuvered into its in vitro and in vivo applications, this review describes future perspective towards the development and therapeutic utilization of the genetic codes, a primary objective of synthetic and chemical biology.
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Affiliation(s)
- Arghya Sett
- ERIN Department, Luxembourg Institute of Science and Technology, 5 Av. des Hauts-Fourneaux, Belval, 4362, Esch, Luxembourg
| | - Manoj Gadewar
- Department of Pharmacology, School of Medical and Allied Sciences, K R Mangalam University, Gurgaon, India
| | - M Arockia Babu
- Institute of Pharmaceutical Research, GLA University, Mathura, India
| | | | | | - Abdulmajeed G Almutary
- Department of Biomedical Sciences, College of Health Sciences, Abu Dhabi University, Abu Dhabi, United Arab Emirates
| | - Vijay Upadhye
- Centre of Research for Development (CR4D) and Department of Microbiology, Parul University, Vadodara, Gujarat, India
| | - Saurabh Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Niraj Kumar Jha
- Centre for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India
- Centre of Research Impact and Outreach, Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, India
- School of Bioengineering & Biosciences, Lovely Professional University, Phagwara, 144411, India
- Department of Biotechnology Engineering and Food Technology, Chandigarh University, Mohali, 140413, India
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4
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Elias M, Guan X, Hudson D, Bose R, Kwak J, Petrounia I, Touah K, Mansour S, Yue P, Errasti G, Delacroix T, Ghosh A, Chakrabarti R. Evolution of Organic Solvent-Resistant DNA Polymerases. ACS Synth Biol 2023; 12:3170-3188. [PMID: 37611245 DOI: 10.1021/acssynbio.2c00515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The introduction of thermostable polymerases revolutionized the polymerase chain reaction (PCR) and biotechnology. However, many GC-rich genes cannot be PCR-amplified with high efficiency in water, irrespective of temperature. Although polar organic cosolvents can enhance nucleic acid polymerization and amplification by destabilizing duplex DNA and secondary structures, nature has not selected for the evolution of solvent-tolerant polymerase enzymes. Here, we used ultrahigh-throughput droplet-based selection and deep sequencing along with computational free-energy and binding affinity calculations to evolve Taq polymerase to generate enzymes that are both stable and highly active in the presence of organic cosolvents, resulting in up to 10% solvent resistance and over 100-fold increase in stability at 97.5 °C in the presence of 1,4-butanediol, as well as tolerance to up to 10 times higher concentrations of the potent cosolvents sulfolane and 2-pyrrolidone. Using these polymerases, we successfully amplified a broad spectrum of GC-rich templates containing regions with over 90% GC content, including templates recalcitrant to amplification with existing polymerases, even in the presence of cosolvents. We also demonstrated dramatically reduced GC bias in the amplification of genes with widely varying GC content in quantitative polymerase chain reaction (qPCR). By expanding the scope of solvent systems compatible with nucleic acid polymerization, these organic solvent-resistant polymerases enable a dramatic reduction of sequence bias not achievable through thermal resistance alone, with significant implications for a wide range of applications including sequencing and synthetic biology in mixed aqueous-organic media.
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Affiliation(s)
- Mohammed Elias
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Xiangying Guan
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Devin Hudson
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Rahul Bose
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Joon Kwak
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Ioanna Petrounia
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Kenza Touah
- Center for Protein Engineering & Drug Discovery, PMC Isochem SAS, 32 Rue Lavoisier, Vert-Le-Petit 91710, France
| | - Sourour Mansour
- Center for Protein Engineering & Drug Discovery, PMC Isochem SAS, 32 Rue Lavoisier, Vert-Le-Petit 91710, France
| | - Peng Yue
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
| | - Gauthier Errasti
- Center for Protein Engineering & Drug Discovery, PMC Isochem SAS, 32 Rue Lavoisier, Vert-Le-Petit 91710, France
| | - Thomas Delacroix
- Center for Protein Engineering & Drug Discovery, PMC Isochem SAS, 32 Rue Lavoisier, Vert-Le-Petit 91710, France
| | - Anisha Ghosh
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
- McGill University, 845 Rue Sherbrooke Ouest, Montreal, QC H3A 0G4, Canada
| | - Raj Chakrabarti
- Chakrabarti Advanced Technology, LLC, PMC Group Building, 1288 Route 73, Suite 110, Mount Laurel, New Jersey 08054, United States
- Center for Protein Engineering & Drug Discovery, PMC Isochem SAS, 32 Rue Lavoisier, Vert-Le-Petit 91710, France
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5
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Gantz M, Neun S, Medcalf EJ, van Vliet LD, Hollfelder F. Ultrahigh-Throughput Enzyme Engineering and Discovery in In Vitro Compartments. Chem Rev 2023; 123:5571-5611. [PMID: 37126602 PMCID: PMC10176489 DOI: 10.1021/acs.chemrev.2c00910] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Indexed: 05/03/2023]
Abstract
Novel and improved biocatalysts are increasingly sourced from libraries via experimental screening. The success of such campaigns is crucially dependent on the number of candidates tested. Water-in-oil emulsion droplets can replace the classical test tube, to provide in vitro compartments as an alternative screening format, containing genotype and phenotype and enabling a readout of function. The scale-down to micrometer droplet diameters and picoliter volumes brings about a >107-fold volume reduction compared to 96-well-plate screening. Droplets made in automated microfluidic devices can be integrated into modular workflows to set up multistep screening protocols involving various detection modes to sort >107 variants a day with kHz frequencies. The repertoire of assays available for droplet screening covers all seven enzyme commission (EC) number classes, setting the stage for widespread use of droplet microfluidics in everyday biochemical experiments. We review the practicalities of adapting droplet screening for enzyme discovery and for detailed kinetic characterization. These new ways of working will not just accelerate discovery experiments currently limited by screening capacity but profoundly change the paradigms we can probe. By interfacing the results of ultrahigh-throughput droplet screening with next-generation sequencing and deep learning, strategies for directed evolution can be implemented, examined, and evaluated.
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Affiliation(s)
| | | | | | | | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Rd, Cambridge CB2 1GA, U.K.
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6
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Akram F, Shah FI, Ibrar R, Fatima T, Haq IU, Naseem W, Gul MA, Tehreem L, Haider G. Bacterial thermophilic DNA polymerases: A focus on prominent biotechnological applications. Anal Biochem 2023; 671:115150. [PMID: 37054862 DOI: 10.1016/j.ab.2023.115150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/24/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
DNA polymerases are the enzymes able to replicate the genetic information in nucleic acid. As a result, they are necessary to copy the complete genome of every living creature before cell division and sustain the integrity of the genetic information throughout the life of each cell. Any organism that uses DNA as its genetic information, whether unicellular or multicellular, requires one or more thermostable DNA polymerases to thrive. Thermostable DNA polymerase is important in modern biotechnology and molecular biology because it results in methods such as DNA cloning, DNA sequencing, whole genome amplification, molecular diagnostics, polymerase chain reaction, synthetic biology, and single nucleotide polymorphism detection. There are at least 14 DNA-dependent DNA polymerases in the human genome, which is remarkable. These include the widely accepted, high-fidelity enzymes responsible for replicating the vast majority of genomic DNA and eight or more specialized DNA polymerases discovered in the last decade. The newly discovered polymerases' functions are still being elucidated. Still, one of its crucial tasks is to permit synthesis to resume despite the DNA damage that stops the progression of replication-fork. One of the primary areas of interest in the research field has been the quest for novel DNA polymerase since the unique features of each thermostable DNA polymerase may lead to the prospective creation of novel reagents. Furthermore, protein engineering strategies for generating mutant or artificial DNA polymerases have successfully generated potent DNA polymerases for various applications. In molecular biology, thermostable DNA polymerases are extremely useful for PCR-related methods. This article examines the role and importance of DNA polymerase in a variety of techniques.
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Affiliation(s)
- Fatima Akram
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan.
| | - Fatima Iftikhar Shah
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan; The University of Lahore, Pakistan
| | - Ramesha Ibrar
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
| | - Taseer Fatima
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
| | - Ikram Ul Haq
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan; Pakistan Academy of Sciences, Islamabad, Pakistan
| | - Waqas Naseem
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
| | - Mahmood Ayaz Gul
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
| | - Laiba Tehreem
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
| | - Ghanoor Haider
- Institute of Industrial Biotechnology, Government College University, Lahore, 54000, Pakistan
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7
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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: 6] [Impact Index Per Article: 3.0] [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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8
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Aggarwal T, Hansen WA, Hong J, Ganguly A, York DM, Khare SD, Izgu EC. Introducing a New Bond-Forming Activity in an Archaeal DNA Polymerase by Structure-Guided Enzyme Redesign. ACS Chem Biol 2022; 17:1924-1936. [PMID: 35776893 DOI: 10.1021/acschembio.2c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA polymerases have evolved to feature a highly conserved activity across the tree of life: formation of, without exception, internucleotidyl O-P linkages. Can this linkage selectivity be overcome by design to produce xenonucleic acids? Here, we report that the structure-guided redesign of an archaeal DNA polymerase, 9°N, exhibits a new activity undetectable in the wild-type enzyme: catalyzing the formation of internucleotidyl N-P linkages using 3'-NH2-ddNTPs. Replacing a metal-binding aspartate in the 9°N active site with asparagine was key to the emergence of this unnatural enzyme activity. MD simulations provided insights into how a single substitution enhances the productive positioning of a 3'-amino nucleophile in the active site. Further remodeling of the protein-nucleic acid interface in the finger subdomain yielded a quadruple-mutant variant (9°N-NRQS) displaying DNA-dependent NP-DNA polymerase activity. In addition, the engineered promiscuity of 9°N-NRQS was leveraged for one-pot synthesis of DNA─NP-DNA copolymers. This work sheds light on the molecular basis of substrate fidelity and latent promiscuity in enzymes.
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Affiliation(s)
- Tushar Aggarwal
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - William A Hansen
- Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Jonathan Hong
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Abir Ganguly
- Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Laboratory for Biomolecular Simulation Research, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Darrin M York
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Laboratory for Biomolecular Simulation Research, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Sagar D Khare
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Enver Cagri Izgu
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States.,Rutgers Center for Lipid Research and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901, United States
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9
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Christensen TA, Lee KY, Gottlieb SZP, Carrier MB, Leconte AM. Mutant polymerases capable of 2′ fluoro-modified nucleic acid synthesis and amplification with improved accuracy. RSC Chem Biol 2022; 3:1044-1051. [PMID: 35975008 PMCID: PMC9347352 DOI: 10.1039/d2cb00064d] [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: 02/28/2022] [Accepted: 06/16/2022] [Indexed: 11/21/2022] Open
Abstract
Nonnatural nucleic acids (xeno nucleic acids, XNA) can possess several useful properties such as expanded reactivity and nuclease resistance, which can enhance the utility of DNA as a biotechnological tool. Native DNA polymerases are unable to synthesize XNA, so, in recent years mutant XNA polymerases have been engineered with sufficient activity for use in processes such as PCR. While substantial improvements have been made, accuracy still needs to be increased by orders of magnitude to approach natural error rates and make XNA polymerases useful for applications that require high fidelity. Here, we systematically evaluate leading Taq DNA polymerase mutants for their fidelity during synthesis of 2′F XNA. To further improve their accuracy, we add mutations that have been shown to increase the fidelity of wild-type Taq polymerases, to some of the best current XNA polymerases (SFM4–3, SFM4–6, and SFP1). The resulting polymerases show significant improvements in synthesis accuracy. In addition to generating more accurate XNA polymerases, this study also informs future polymerase engineering efforts by demonstrating that mutations that improve the accuracy of DNA synthesis may also have utility in improving the accuracy of XNA synthesis. Polymerases that have been evolved to synthesize 2′F XNA are often inaccurate. Here, we show that you can improve the accuracy of 2′F XNA polymerase synthesis by adding mutations previously found to improve the accuracy of natural DNA synthesis.![]()
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Affiliation(s)
- Trevor A. Christensen
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, USA
| | - Kristi Y. Lee
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, USA
| | - Simone Z. P. Gottlieb
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, USA
| | - Mikayla B. Carrier
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, USA
| | - Aaron M. Leconte
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, USA
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10
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Manandhar M, Chun E, Romesberg FE. Genetic Code Expansion: Inception, Development, Commercialization. J Am Chem Soc 2021; 143:4859-4878. [DOI: 10.1021/jacs.0c11938] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Miglena Manandhar
- Synthorx, a Sanofi Company, La Jolla, California 92037, United States
| | - Eugene Chun
- Synthorx, a Sanofi Company, La Jolla, California 92037, United States
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11
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Siau JW, Nonis S, Chee S, Koh LQ, Ferrer FJ, Brown CJ, Ghadessy FJ. Directed co-evolution of interacting protein-peptide pairs by compartmentalized two-hybrid replication (C2HR). Nucleic Acids Res 2021; 48:e128. [PMID: 33104786 PMCID: PMC7736784 DOI: 10.1093/nar/gkaa933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 10/02/2020] [Accepted: 10/07/2020] [Indexed: 12/21/2022] Open
Abstract
Directed evolution methodologies benefit from read-outs quantitatively linking genotype to phenotype. We therefore devised a method that couples protein–peptide interactions to the dynamic read-out provided by an engineered DNA polymerase. Fusion of a processivity clamp protein to a thermostable nucleic acid polymerase enables polymerase activity and DNA amplification in otherwise prohibitive high-salt buffers. Here, we recapitulate this phenotype by indirectly coupling the Sso7d processivity clamp to Taq DNA polymerase via respective fusion to a high affinity and thermostable interacting protein–peptide pair. Escherichia coli cells co-expressing protein–peptide pairs can directly be used in polymerase chain reactions to determine relative interaction strengths by the measurement of amplicon yields. Conditional polymerase activity is further used to link genotype to phenotype of interacting protein–peptide pairs co-expressed in E. coli using the compartmentalized self-replication directed evolution platform. We validate this approach, termed compartmentalized two-hybrid replication, by selecting for high-affinity peptides that bind two model protein partners: SpyCatcher and the large fragment of NanoLuc luciferase. We further demonstrate directed co-evolution by randomizing both protein and peptide components of the SpyCatcher–SpyTag pair and co-selecting for functionally interacting variants.
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Affiliation(s)
- Jia Wei Siau
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Samuel Nonis
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Sharon Chee
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Li Quan Koh
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Fernando J Ferrer
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Christopher J Brown
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
| | - Farid J Ghadessy
- p53 Laboratory, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, 138648, Singapore
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12
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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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13
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Špaček J, Karalkar N, Fojta M, Wang J, Benner SA. Electrochemical reduction and oxidation of eight unnatural 2′-deoxynucleosides at a pyrolytic graphite electrode. Electrochim Acta 2020; 362. [DOI: 10.1016/j.electacta.2020.137210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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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: 69] [Impact Index Per Article: 17.3] [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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15
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Abstract
DNA polymerases play a central role in biology by transferring genetic information from one generation to the next during cell division. Harnessing the power of these enzymes in the laboratory has fueled an increase in biomedical applications that involve the synthesis, amplification, and sequencing of DNA. However, the high substrate specificity exhibited by most naturally occurring DNA polymerases often precludes their use in practical applications that require modified substrates. Moving beyond natural genetic polymers requires sophisticated enzyme-engineering technologies that can be used to direct the evolution of engineered polymerases that function with tailor-made activities. Such efforts are expected to uniquely drive emerging applications in synthetic biology by enabling the synthesis, replication, and evolution of synthetic genetic polymers with new physicochemical properties.
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16
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Neun S, Zurek PJ, Kaminski TS, Hollfelder F. Ultrahigh throughput screening for enzyme function in droplets. Methods Enzymol 2020; 643:317-343. [PMID: 32896286 DOI: 10.1016/bs.mie.2020.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Water-in-oil droplets, made and handled in microfluidic devices, provide a new experimental format, in which ultrahigh throughput experiments can be conducted faster and with minimal reagent consumption. An increasing number of studies have emerged that applied this approach to directed evolution and metagenomic screening of enzyme catalysts. Here, we review the considerations necessary to implement robust workflows, based on choices of device design, detection modes, emulsion formulations and substrates, and scope out which enzyme classes have become amenable to droplet screening.
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Affiliation(s)
- Stefanie Neun
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Paul J Zurek
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Tomasz S Kaminski
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
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17
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Zhukov SA, Fokina AA, Stetsenko DA, Vasilyeva SV. Methods for Molecular Evolution of Polymerases. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019060426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Abstract
The combination of modern biotechnologies such as DNA synthesis, λ red recombineering, CRISPR-based editing and next-generation high-throughput sequencing increasingly enables precise manipulation of genes and genomes. Beyond rational design, these technologies also enable the targeted, and potentially continuous, introduction of multiple mutations. While this might seem to be merely a return to natural selection, the ability to target evolution greatly reduces fitness burdens and focuses mutation and selection on those genes and traits that best contribute to a desired phenotype, ultimately throwing evolution into fast forward.
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19
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Engineering Polymerases for New Functions. Trends Biotechnol 2019; 37:1091-1103. [PMID: 31003719 DOI: 10.1016/j.tibtech.2019.03.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/08/2019] [Accepted: 03/19/2019] [Indexed: 01/04/2023]
Abstract
DNA polymerases are critical tools in biotechnology, enabling efficient and accurate amplification of DNA templates, yet many desired functions are not readily available in natural DNA polymerases. New or improved functions can be engineered in DNA polymerases by mutagenesis or through the creation of protein chimeras. Engineering often necessitates the development of new techniques, such as selections in water-in-oil emulsions that connect genotype to phenotype and allow more flexibility in engineering than phage display. Engineering efforts have led to DNA polymerases that can withstand extreme conditions or the presence of inhibitors, as well as polymerases with the ability to copy modified DNA templates. In this review we discuss polymerases for biotechnology that have been reported along with tools to enable further development.
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20
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Identification of Thermus aquaticus DNA polymerase variants with increased mismatch discrimination and reverse transcriptase activity from a smart enzyme mutant library. Sci Rep 2019; 9:590. [PMID: 30679705 PMCID: PMC6345897 DOI: 10.1038/s41598-018-37233-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/02/2018] [Indexed: 12/13/2022] Open
Abstract
DNA polymerases the key enzymes for several biotechnological applications. Obviously, nature has not evolved these enzymes to be compatible with applications in biotechnology. Thus, engineering of a natural scaffold of DNA polymerases may lead to enzymes improved for several applications. Here, we investigated a two-step approach for the design and construction of a combinatorial library of mutants of KlenTaq DNA polymerase. First, we selected amino acid sites for saturation mutagenesis that interact with the primer/template strands or are evolutionarily conserved. From this library, we identified mutations that little interfere with DNA polymerase activity. Next, these functionally active mutants were combined randomly to construct a second library with enriched sequence diversity. We reasoned that the combination of mutants that have minuscule effect on enzyme activity and thermostability, will result in entities that have an increased mutation load but still retain activity. Besides activity and thermostability, we screened the library for entities with two distinct properties. Indeed, we identified two different KlenTaq DNA polymerase variants that either exhibit increased mismatch extension discrimination or increased reverse transcription PCR activity, respectively.
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21
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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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22
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Abil Z, Ellefson JW, Gollihar JD, Watkins E, Ellington AD. Compartmentalized partnered replication for the directed evolution of genetic parts and circuits. Nat Protoc 2017; 12:2493-2512. [PMID: 29120463 DOI: 10.1038/nprot.2017.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Compartmentalized partnered replication (CPR) is an emulsion-based directed evolution method based on a robust and modular phenotype-genotype linkage. In contrast to other in vivo directed evolution approaches, CPR largely mitigates host fitness effects due to a relatively short expression time of the gene of interest. CPR is based on gene circuits in which the selection of a 'partner' function from a library leads to the production of a thermostable polymerase. After library preparation, bacteria produce partner proteins that can potentially lead to enhancement of transcription, translation, gene regulation, and other aspects of cellular metabolism that reinforce thermostable polymerase production. Individual cells are then trapped in water-in-oil emulsion droplets in the presence of primers and dNTPs, followed by the recovery of the partner genes via emulsion PCR. In this step, droplets with cells expressing partner proteins that promote polymerase production will produce higher copy numbers of the improved partner gene. The resulting partner genes can subsequently be recloned for the next round of selection. Here, we present a step-by-step guideline for the procedure by providing examples of (i) selection of T7 RNA polymerases that recognize orthogonal promoters and (ii) selection of tRNA for enhanced amber codon suppression. A single round of CPR should take ∼3-5 d, whereas a whole directed evolution can be performed in 3-10 rounds, depending on selection efficiency.
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Affiliation(s)
- Zhanar Abil
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, USA
| | - Jared W Ellefson
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, USA
| | - Jimmy D Gollihar
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, USA
| | - Ella Watkins
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, USA
| | - Andrew D Ellington
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas, USA.,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, USA.,Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, USA
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23
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Agudo R, Calvo PA, Martínez-Jiménez MI, Blanco L. Engineering human PrimPol into an efficient RNA-dependent-DNA primase/polymerase. Nucleic Acids Res 2017; 45:9046-9058. [PMID: 28911121 PMCID: PMC5587808 DOI: 10.1093/nar/gkx633] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/12/2017] [Indexed: 02/01/2023] Open
Abstract
We have developed a straightforward fluorometric assay to measure primase-polymerase activity of human PrimPol (HsPrimPol). The sensitivity of this procedure uncovered a novel RNA-dependent DNA priming-polymerization activity (RdDP) of this enzyme. In an attempt to enhance HsPrimPol RdDP activity, we constructed a smart mutant library guided by prior sequence-function analysis, and tested this library in an adapted screening platform of our fluorometric assay. After screening less than 500 variants, we found a specific HsPrimPol mutant, Y89R, which displays 10-fold higher RdDP activity than the wild-type enzyme. The improvement of RdDP activity in the Y89R variant was due mainly to an increased in the stabilization of the preternary complex (protein:template:incoming nucleotide), a specific step preceding dimer formation. Finally, in support of the biotechnological potential of PrimPol as a DNA primer maker during reverse transcription, mutant Y89R HsPrimPol rendered up to 17-fold more DNA than with random hexamer primers.
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Affiliation(s)
- Rubén Agudo
- Centro de Biología Molecular ‘Severo Ochoa’ (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 91 196 46 85; Fax: +34 91 196 44 20; . Correspondence may also be addressed to Rubén Agudo. Tel: +34 91 196 46 86; Fax: +34 91 196 44 20;
| | - Patricia A. Calvo
- Centro de Biología Molecular ‘Severo Ochoa’ (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | | | - Luis Blanco
- Centro de Biología Molecular ‘Severo Ochoa’ (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 91 196 46 85; Fax: +34 91 196 44 20; . Correspondence may also be addressed to Rubén Agudo. Tel: +34 91 196 46 86; Fax: +34 91 196 44 20;
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24
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DNA polymerases and biotechnological applications. Curr Opin Biotechnol 2017; 48:187-195. [PMID: 28618333 DOI: 10.1016/j.copbio.2017.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 04/17/2017] [Indexed: 01/04/2023]
Abstract
A multitude of biotechnological techniques used in basic research as well as in clinical diagnostics on an everyday basis depend on DNA polymerases and their intrinsic capability to replicate DNA strands with astoundingly high fidelity. Applications with fundamental importance to modern molecular biology, including the polymerase chain reaction and DNA sequencing, would not be feasible without the advances made in characterizing these enzymes over the course of the last 60 years. Nonetheless, the still growing application scope of DNA polymerases necessitates the identification of novel enzymes with tailor-made properties. In the recent past, DNA polymerases optimized for diverse PCR and sequencing applications as well as enzymes that accept a variety of unnatural substrates for the synthesis and reverse transcription of modified nucleic acids have been developed.
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25
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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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26
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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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27
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Rosenblum SL, Weiden AG, Lewis EL, Ogonowsky AL, Chia HE, Barrett SE, Liu MD, Leconte AM. Design and Discovery of New Combinations of Mutant DNA Polymerases and Modified DNA Substrates. Chembiochem 2017; 18:816-823. [PMID: 28160372 DOI: 10.1002/cbic.201600701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Indexed: 11/06/2022]
Abstract
Chemical modifications can enhance the properties of DNA by imparting nuclease resistance and generating more-diverse physical structures. However, native DNA polymerases generally cannot synthesize significant lengths of DNA with modified nucleotide triphosphates. Previous efforts have identified a mutant of DNA polymerase I from Thermus aquaticus DNA (SFM19) as capable of synthesizing a range of short, 2'-modified DNAs; however, it is limited in the length of the products it can synthesize. Here, we rationally designed and characterized ten mutants of SFM19. From this, we identified enzymes with substantially improved activity for the synthesis of 2'F-, 2'OH-, 2'OMe-, and 3'OMe-modified DNA as well as for reverse transcription of 2'OMe DNA. We also evaluated mutant DNA polymerases previously only tested for synthesis for 2'OMe DNA and showed that they are capable of an expanded range of modified DNA synthesis. This work significantly expands the known combinations of modified DNA and Taq DNA polymerase mutants.
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Affiliation(s)
- Sydney L Rosenblum
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Aurora G Weiden
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Eliza L Lewis
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Alexie L Ogonowsky
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Hannah E Chia
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Susanna E Barrett
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Mira D Liu
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
| | - Aaron M Leconte
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, 91711, USA
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28
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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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29
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Dellafiore MA, Montserrat JM, Iribarren AM. Modified Nucleoside Triphosphates for In-vitro Selection Techniques. Front Chem 2016; 4:18. [PMID: 27200340 PMCID: PMC4854868 DOI: 10.3389/fchem.2016.00018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/05/2016] [Indexed: 12/22/2022] Open
Abstract
The development of SELEX (Selective Enhancement of Ligands by Exponential Enrichment) provides a powerful tool for the search of functional oligonucleotides with the ability to bind ligands with high affinity and selectivity (aptamers) and for the discovery of nucleic acid sequences with diverse enzymatic activities (ribozymes and DNAzymes). This technique has been extensively applied to the selection of natural DNA or RNA molecules but, in order to improve chemical and structural diversity as well as for particular applications where further chemical or biological stability is necessary, the extension of this strategy to modified oligonucleotides is desirable. Taking into account these needs, this review intends to collect the research carried out during the past years, focusing mainly on the use of modified nucleotides in SELEX and the development of mutant enzymes for broadening nucleoside triphosphates acceptance. In addition, comments regarding the synthesis of modified nucleoside triphosphate will be briefly discussed.
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Affiliation(s)
- María A Dellafiore
- Laboratorio de Química de Ácidos Nucleicos, INGEBI (CONICET) Ciudad Autónoma de Buenos Aires, Argentina
| | - Javier M Montserrat
- Laboratorio de Química de Ácidos Nucleicos, INGEBI (CONICET)Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Ciencias, Universidad Nacional de General SarmientoLos Polvorines, Argentina
| | - Adolfo M Iribarren
- Laboratorio de Química de Ácidos Nucleicos, INGEBI (CONICET)Ciudad Autónoma de Buenos Aires, Argentina; Laboratorio de Biotransformaciones, Universidad Nacional de QuilmesBernal, Argentina
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30
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Schultz HJ, Gochi AM, Chia HE, Ogonowsky AL, Chiang S, Filipovic N, Weiden AG, Hadley EE, Gabriel SE, Leconte AM. Taq DNA Polymerase Mutants and 2'-Modified Sugar Recognition. Biochemistry 2015; 54:5999-6008. [PMID: 26334839 DOI: 10.1021/acs.biochem.5b00689] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical modifications to DNA, such as 2' modifications, are expected to increase the biotechnological utility of DNA; however, these modified forms of DNA are limited by their inability to be effectively synthesized by DNA polymerase enzymes. Previous efforts have identified mutant Thermus aquaticus DNA polymerase I (Taq) enzymes capable of recognizing 2'-modified DNA nucleotides. While these mutant enzymes recognize these modified nucleotides, they are not capable of synthesizing full length modified DNA; thus, further engineering is required for these enzymes. Here, we describe comparative biochemical studies that identify useful, but previously uncharacterized, properties of these enzymes; one enzyme, SFM19, is able to recognize a range of 2'-modified nucleotides much wider than that previously examined, including fluoro, azido, and amino modifications. To understand the molecular origins of these differences, we also identify specific amino acids and combinations of amino acids that contribute most to the previously evolved unnatural activity. Our data suggest that a negatively charged amino acid at 614 and mutation of the steric gate residue, E615, to glycine make up the optimal combination for modified oligonucleotide synthesis. These studies yield an improved understanding of the mutational origins of 2'-modified substrate recognition as well as identify SFM19 as the best candidate for further engineering, whether via rational design or directed evolution.
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Affiliation(s)
- Hayley J Schultz
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Andrea M Gochi
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Hannah E Chia
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Alexie L Ogonowsky
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Sharon Chiang
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Nedim Filipovic
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Aurora G Weiden
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Emma E Hadley
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Sara E Gabriel
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Aaron M Leconte
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
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31
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Colin PY, Zinchenko A, Hollfelder F. Enzyme engineering in biomimetic compartments. Curr Opin Struct Biol 2015; 33:42-51. [PMID: 26311177 DOI: 10.1016/j.sbi.2015.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/12/2015] [Accepted: 06/04/2015] [Indexed: 12/25/2022]
Abstract
The success of a directed evolution approach to creating custom-made enzymes relies in no small part on screening as many clones as possible. The miniaturisation of assays into pico to femtoliter compartments (emulsion droplets, vesicles or gel-shell beads) makes directed evolution campaigns practically more straightforward than current large scale industrial screening that requires liquid handling equipment and much manpower. Several recent experimental formats have established protocols to screen more than 10 million compartments per day, representing unprecedented throughput at low cost. This review introduces the emerging approaches towards making biomimetic man-made compartments that are poised to be adapted by a wider circle of researchers. In addition to cost and time saving, control of selection pressures and conditions, the quantitative readout that reports on every library members and the ability to develop strategies based on these data will increase the degrees of freedom in designing and testing strategies for directed evolution experiments.
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Affiliation(s)
- Pierre-Yves Colin
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | | | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK.
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Millar D, Christova Y, Holliger P. A polymerase engineered for bisulfite sequencing. Nucleic Acids Res 2015; 43:e155. [PMID: 26271989 PMCID: PMC4678845 DOI: 10.1093/nar/gkv798] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/27/2015] [Indexed: 01/17/2023] Open
Abstract
Bisulfite sequencing is a key methodology in epigenetics. However, the standard workflow of bisulfite sequencing involves heat and strongly basic conditions to convert the intermediary product 5,6-dihydrouridine-6-sulfonate (dhU6S) (generated by reaction of bisulfite with deoxycytidine (dC)) to uracil (dU). These harsh conditions generally lead to sample loss and DNA damage while milder conditions may result in incomplete conversion of intermediates to uracil. Both can lead to poor recovery of bisulfite-treated DNA by the polymerase chain reaction (PCR) as either damaged DNA and/or intermediates of bisulfite treatment are poor substrate for standard DNA polymerases. Here we describe an engineered DNA polymerase (5D4) with an enhanced ability to replicate and PCR amplify bisulfite-treated DNA due to an ability to bypass both DNA lesions and bisulfite intermediates, allowing significantly milder conversion conditions and increased sensitivity in the PCR amplification of bisulfite-treated DNA. Incorporation of the 5D4 DNA polymerase into the bisulfite sequencing workflow thus promises significant sensitivity and efficiency gains.
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Affiliation(s)
- Doug Millar
- Genetic Signatures, Level 9, Lowy Packer Building 405, Liverpool Street, Darlinghurst 2010, Sydney, Australia
| | - Yonka Christova
- 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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Ingale SA, Leonard P, Yang H, Seela F. 5-Nitroindole oligonucleotides with alkynyl side chains: universal base pairing, triple bond hydration and properties of pyrene "click" adducts. Org Biomol Chem 2015; 12:8519-32. [PMID: 25236942 DOI: 10.1039/c4ob01478b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Oligonucleotides with 3-ethynyl-5-nitroindole and 3-octadiynyl-5-nitroindole 2'-deoxyribonucleosides were prepared by solid-phase synthesis. To this end, nucleoside phosphoramidites with clickable side chains were synthesized. The 3-ethynylated 5-nitroindole nucleoside was hydrated during automatized DNA synthesis to 3-acetyl-5-nitroindole 2'-deoxyribonucleoside. Side product formation was circumvented by triisopropylsilyl protection of the ethynyl side chain and was removed with TBAF after oligonucleotide synthesis. All compounds with a clickable 5-nitroindole skeleton show universal base pairing and can be functionalized with almost any azide in any position of the DNA chain. Functionalization of the side chain with 1-azidomethylpyrene afforded click adducts in which the fluorescence was quenched by the 5-nitroindole moieties. However, fluorescence was slightly recovered during duplex formation. Oligonucleotides with a pyrene residue and a long linker arm are stabilized over those with non-functionalized side chains. From the UV red shift of the pyrene residue in oligonucleotides and modelling studies, pyrene intercalation was established for the long linker adduct showing increased duplex stability over those with a short side chain.
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Affiliation(s)
- Sachin A Ingale
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany
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Currin A, Swainston N, Day PJ, Kell DB. Synthetic biology for the directed evolution of protein biocatalysts: navigating sequence space intelligently. Chem Soc Rev 2015; 44:1172-239. [PMID: 25503938 PMCID: PMC4349129 DOI: 10.1039/c4cs00351a] [Citation(s) in RCA: 251] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Indexed: 12/21/2022]
Abstract
The amino acid sequence of a protein affects both its structure and its function. Thus, the ability to modify the sequence, and hence the structure and activity, of individual proteins in a systematic way, opens up many opportunities, both scientifically and (as we focus on here) for exploitation in biocatalysis. Modern methods of synthetic biology, whereby increasingly large sequences of DNA can be synthesised de novo, allow an unprecedented ability to engineer proteins with novel functions. However, the number of possible proteins is far too large to test individually, so we need means for navigating the 'search space' of possible protein sequences efficiently and reliably in order to find desirable activities and other properties. Enzymologists distinguish binding (Kd) and catalytic (kcat) steps. In a similar way, judicious strategies have blended design (for binding, specificity and active site modelling) with the more empirical methods of classical directed evolution (DE) for improving kcat (where natural evolution rarely seeks the highest values), especially with regard to residues distant from the active site and where the functional linkages underpinning enzyme dynamics are both unknown and hard to predict. Epistasis (where the 'best' amino acid at one site depends on that or those at others) is a notable feature of directed evolution. The aim of this review is to highlight some of the approaches that are being developed to allow us to use directed evolution to improve enzyme properties, often dramatically. We note that directed evolution differs in a number of ways from natural evolution, including in particular the available mechanisms and the likely selection pressures. Thus, we stress the opportunities afforded by techniques that enable one to map sequence to (structure and) activity in silico, as an effective means of modelling and exploring protein landscapes. Because known landscapes may be assessed and reasoned about as a whole, simultaneously, this offers opportunities for protein improvement not readily available to natural evolution on rapid timescales. Intelligent landscape navigation, informed by sequence-activity relationships and coupled to the emerging methods of synthetic biology, offers scope for the development of novel biocatalysts that are both highly active and robust.
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Affiliation(s)
- Andrew Currin
- Manchester Institute of Biotechnology , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK . ; http://dbkgroup.org/; @dbkell ; Tel: +44 (0)161 306 4492
- School of Chemistry , The University of Manchester , Manchester M13 9PL , UK
- Centre for Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM) , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK
| | - Neil Swainston
- Manchester Institute of Biotechnology , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK . ; http://dbkgroup.org/; @dbkell ; Tel: +44 (0)161 306 4492
- Centre for Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM) , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK
- School of Computer Science , The University of Manchester , Manchester M13 9PL , UK
| | - Philip J. Day
- Manchester Institute of Biotechnology , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK . ; http://dbkgroup.org/; @dbkell ; Tel: +44 (0)161 306 4492
- Centre for Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM) , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK
- Faculty of Medical and Human Sciences , The University of Manchester , Manchester M13 9PT , UK
| | - Douglas B. Kell
- Manchester Institute of Biotechnology , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK . ; http://dbkgroup.org/; @dbkell ; Tel: +44 (0)161 306 4492
- School of Chemistry , The University of Manchester , Manchester M13 9PL , UK
- Centre for Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM) , The University of Manchester , 131, Princess St , Manchester M1 7DN , UK
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Fujita H, Nakajima K, Kasahara Y, Ozaki H, Kuwahara M. Polymerase-mediated high-density incorporation of amphiphilic functionalities into DNA: enhancement of nuclease resistance and stability in human serum. Bioorg Med Chem Lett 2014; 25:333-6. [PMID: 25475204 DOI: 10.1016/j.bmcl.2014.11.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 12/20/2022]
Abstract
Modified oligodeoxyribonucleotides (mdODNs) bearing multiple copies of an amphiphilic functional group were enzymatically synthesized by simultaneous incorporation of base-modified 5'-triphosphate analogs of 2'-deoxyguanosine (dG(am)TP), 2'-deoxyuridine (dU(am)TP), 2'-deoxyadenosine (dA(am)TP), and 2'-deoxycytosine (dC(am)TP). The amphiphilic functionality, that is, (E)-38,53-dioxo-2,5,8,11,14,17,20,23,26,29,32,35-dodecaoxa-39,52-diazapentapentacont-54-en-55-yl group, consists of the water soluble dodeca(ethylene glycol) chain and the hydrophobic dodecyl chain. An enzymatically synthesized ODN, composed of a 20-mer 5'-terminal segment containing 2'-O,4'-C-methylene-bridged/linked bicyclic ribonucleotide (B/L nucleotide) and a 12-mer 3'-terminal segment containing the nucleobase-modified analogs, exhibits very high resistance against phosphodiesterase I and is stable in human serum for a longer period when compared with ODN, where the 12-mer 3'-terminal segment contains unmodified nucleotides.
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Affiliation(s)
- Hiroto Fujita
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Kohsuke Nakajima
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Yuuya Kasahara
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan; National Institute of Biomedical Innovation (NIBIO), 7-6-8 Asagi, Saito, Ibaraki, Osaka 567-0085, Japan
| | - Hiroaki Ozaki
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Masayasu Kuwahara
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
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Laos R, Thomson JM, Benner SA. DNA polymerases engineered by directed evolution to incorporate non-standard nucleotides. Front Microbiol 2014; 5:565. [PMID: 25400626 PMCID: PMC4215692 DOI: 10.3389/fmicb.2014.00565] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/07/2014] [Indexed: 11/13/2022] Open
Abstract
DNA polymerases have evolved for billions of years to accept natural nucleoside triphosphate substrates with high fidelity and to exclude closely related structures, such as the analogous ribonucleoside triphosphates. However, polymerases that can accept unnatural nucleoside triphosphates are desired for many applications in biotechnology. The focus of this review is on non-standard nucleotides that expand the genetic "alphabet." This review focuses on experiments that, by directed evolution, have created variants of DNA polymerases that are better able to accept unnatural nucleotides. In many cases, an analysis of past evolution of these polymerases (as inferred by examining multiple sequence alignments) can help explain some of the mutations delivered by directed evolution.
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Affiliation(s)
- Roberto Laos
- Foundation for Applied Molecular Evolution Gainesville, FL, USA
| | | | - Steven A Benner
- Foundation for Applied Molecular Evolution Gainesville, FL, USA
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Hou D, Greenberg MM. DNA interstrand cross-linking upon irradiation of aryl halide C-nucleotides. J Org Chem 2014; 79:1877-84. [PMID: 24559326 DOI: 10.1021/jo4028227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
γ-Radiolysis kills cells by damaging DNA via radical processes. Many of the radical pathways are O2 dependent, which results in a reduction in the cytotoxicity of ionizing radiation in hypoxic tumor cells. Consequently, there is a need for chemical agents that increase DNA damage by ionizing radiation under O2-deficient conditions. Modified nucleotides that are incorporated in DNA and produce highly reactive σ-radicals are useful as radiosensitizing agents. Aryl halide C-nucleotides (4-6) were incorporated into oligonucleotides by solid-phase synthesis. Duplex DNA containing 4-6 forms interstrand cross-links upon γ-radiolysis under anaerobic conditions or UV irradiation. Deep Vent (exo(-)) DNA polymerase accepted the nucleotide triphosphate of C-nucleotide 6 as a substrate and preferentially incorporated it opposite pyrimidines, but no further extension was detected. Incorporation of 6 in extended products by Deep Vent (exo(-)) during PCR or by Sequenase during copying of single stranded DNA plasmid was undetectable. Aryl halide nucleotide analogues that produce DNA interstrand cross-links under anaerobic conditions upon irradiation are potentially useful as radiosensitizing agents, but further research is needed to identify molecules that are incorporated by DNA polymerases and do not block further polymerization for this approach to be useful in cells.
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Affiliation(s)
- Dianjie Hou
- Department of Chemistry Johns Hopkins University 3400 North Charles Street, Baltimore, Maryland 21218, United States
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38
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Chen T, Romesberg FE. Directed polymerase evolution. FEBS Lett 2013; 588:219-29. [PMID: 24211837 DOI: 10.1016/j.febslet.2013.10.040] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 10/28/2013] [Accepted: 10/29/2013] [Indexed: 12/23/2022]
Abstract
Polymerases evolved in nature to synthesize DNA and RNA, and they underlie the storage and flow of genetic information in all cells. The availability of these enzymes for use at the bench has driven a revolution in biotechnology and medicinal research; however, polymerases did not evolve to function efficiently under the conditions required for some applications and their high substrate fidelity precludes their use for most applications that involve modified substrates. To circumvent these limitations, researchers have turned to directed evolution to tailor the properties and/or substrate repertoire of polymerases for different applications, and several systems have been developed for this purpose. These systems draw on different methods of creating a pool of randomly mutated polymerases and are differentiated by the process used to isolate the most fit members. A variety of polymerases have been evolved, providing new or improved functionality, as well as interesting new insight into the factors governing activity.
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Affiliation(s)
- Tingjian Chen
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Floyd E Romesberg
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
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39
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Tee KL, Wong TS. Polishing the craft of genetic diversity creation in directed evolution. Biotechnol Adv 2013; 31:1707-21. [PMID: 24012599 DOI: 10.1016/j.biotechadv.2013.08.021] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/31/2013] [Accepted: 08/31/2013] [Indexed: 12/25/2022]
Abstract
Genetic diversity creation is a core technology in directed evolution where a high quality mutant library is crucial to its success. Owing to its importance, the technology in genetic diversity creation has seen rapid development over the years and its application has diversified into other fields of scientific research. The advances in molecular cloning and mutagenesis since 2008 were reviewed. Specifically, new cloning techniques were classified based on their principles of complementary overhangs, homologous sequences, overlapping PCR and megaprimers and the advantages, drawbacks and performances of these methods were highlighted. New mutagenesis methods developed for random mutagenesis, focused mutagenesis and DNA recombination were surveyed. The technical requirements of these methods and the mutational spectra were compared and discussed with references to commonly used techniques. The trends of mutant library preparation were summarised. Challenges in genetic diversity creation were discussed with emphases on creating "smart" libraries, controlling the mutagenesis spectrum and specific challenges in each group of mutagenesis methods. An outline of the wider applications of genetic diversity creation includes genome engineering, viral evolution, metagenomics and a study of protein functions. The review ends with an outlook for genetic diversity creation and the prospective developments that can have future impact in this field.
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Affiliation(s)
- Kang Lan Tee
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, England, United Kingdom
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40
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Wynne SA, Pinheiro VB, Holliger P, Leslie AGW. Structures of an apo and a binary complex of an evolved archeal B family DNA polymerase capable of synthesising highly cy-dye labelled DNA. PLoS One 2013; 8:e70892. [PMID: 23940661 PMCID: PMC3733885 DOI: 10.1371/journal.pone.0070892] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 06/24/2013] [Indexed: 11/18/2022] Open
Abstract
Thermophilic DNA polymerases of the polB family are of great importance in biotechnological applications including high-fidelity PCR. Of particular interest is the relative promiscuity of engineered versions of the exo- form of polymerases from the Thermo- and Pyrococcales families towards non-canonical substrates, which enables key advances in Next-generation sequencing. Despite this there is a paucity of structural information to guide further engineering of this group of polymerases. Here we report two structures, of the apo form and of a binary complex of a previously described variant (E10) of Pyrococcus furiosus (Pfu) polymerase with an ability to fully replace dCTP with Cyanine dye-labeled dCTP (Cy3-dCTP or Cy5-dCTP) in PCR and synthesise highly fluorescent “CyDNA” densely decorated with cyanine dye heterocycles. The apo form of Pfu-E10 closely matches reported apo form structures of wild-type Pfu. In contrast, the binary complex (in the replicative state with a duplex DNA oligonucleotide) reveals a closing movement of the thumb domain, increasing the contact surface with the nascent DNA duplex strand. Modelling based on the binary complex suggests how bulky fluorophores may be accommodated during processive synthesis and has aided the identification of residues important for the synthesis of unnatural nucleic acid polymers.
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Affiliation(s)
- Samantha A. Wynne
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Vitor B. Pinheiro
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Philipp Holliger
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Andrew G. W. Leslie
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
- * E-mail:
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41
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Nakano SI, Uotani Y, Sato Y, Oka H, Fujii M, Sugimoto N. Conformational changes of the phenyl and naphthyl isocyanate-DNA adducts during DNA replication and by minor groove binding molecules. Nucleic Acids Res 2013; 41:8581-90. [PMID: 23873956 PMCID: PMC3794578 DOI: 10.1093/nar/gkt608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
DNA lesions produced by aromatic isocyanates have an extra bulky group on the nucleotide bases, with the capability of forming stacking interaction within a DNA helix. In this work, we investigated the conformation of the 2′-deoxyadenosine and 2′-deoxycytidine derivatives tethering a phenyl or naphthyl group, introduced in a DNA duplex. The chemical modification experiments using KMnO4 and 1-cyclohexyl-3 -(2-morpholinoethyl) carbodiimide metho-p-toluenesulfonate have shown that the 2′-deoxycytidine lesions form the base pair with guanine while the 2′-deoxyadenosine lesions have less ability of forming the base pair with thymine in solution. Nevertheless, the kinetic analysis shows that these DNA lesions are compatible with DNA ligase and DNA polymerase reactions, as much as natural DNA bases. We suggest that the adduct lesions have a capability of adopting dual conformations, depending on the difference in their interaction energies between stacking of the attached aromatic group and base pairing through hydrogen bonds. It is also presented that the attached aromatic groups change their orientation by interacting with the minor groove binding netropsin, distamycin and synthetic polyamide. The nucleotide derivatives would be useful for enhancing the phenotypic diversity of DNA molecules and for exploring new non-natural nucleotides.
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Affiliation(s)
- Shu-ichi Nakano
- Department of Nanobiochemistry, Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan, Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan, Department of Chemistry, Faculty of Science and Engineering, Konan University, 8-9-1, Okamoto, Higashinada-ku, Kobe, 658-8501, Japan, Molecular Engineering Institute (MEI), Kinki University, 11-6 Kayanomori, Iizuka, Fukuoka, 820-8555, Japan and Department of Environmental and Biological Chemistry, Kinki University, 11-6 Kayanomori, Iizuka, Fukuoka, 820-8555, Japan
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42
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Gloeckner C, Kranaster R, Marx A. Directed evolution of DNA polymerases: construction and screening of DNA polymerase mutant libraries. ACTA ACUST UNITED AC 2013; 2:89-109. [PMID: 23836552 DOI: 10.1002/9780470559277.ch090183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The protocols in this article describe the construction of a mutant DNA polymerase library using error-prone PCR (epPCR) as a method for gene randomization, followed by screening of the library using two different approaches. The examples described use an N-terminally truncated form of the thermostable DNA polymerase I of Thermus aquaticus (Taq DNA polymerase), namely Klentaq (KTQ), and protocols are included for the identification of variants with (1) increased DNA lesion-bypass ability and (2) enhanced selectivity for DNA match/mismatch recognition. The screening assays are based on double-stranded DNA detection (using SYBR Green I) which can be carried out using standard laboratory equipment. The described assays are designed for use in a 384-well plate format to increase screening throughput and reduce material costs. For improved accuracy and ease of liquid handling, the use of an automated liquid handling device is recommended. Curr. Protoc. Chem Biol. 2:89-109. © 2010 by John Wiley & Sons, Inc.
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Abstract
For over 20 years, laboratories around the world have been applying the principles of Darwinian evolution to isolate DNA and RNA molecules with specific ligand-binding or catalytic activities. This area of synthetic biology, commonly referred to as in vitro genetics, is made possible by the availability of natural polymerases that can replicate genetic information in the laboratory. Moving beyond natural nucleic acids requires organic chemistry to synthesize unnatural analogues and polymerase engineering to create enzymes that recognize artificial substrates. Progress in both of these areas has led to the emerging field of synthetic genetics, which explores the structural and functional properties of synthetic genetic polymers by in vitro evolution. This review examines recent advances in the Darwinian evolution of artificial genetic polymers and their potential downstream applications in exobiology, molecular medicine, and synthetic biology.
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Affiliation(s)
- John C Chaput
- Center for Evolutionary Medicine and Informatics in the Biodesign Institute, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-5301, USA.
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44
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Liang F, Liu YZ, Zhang P. Universal base analogues and their applications in DNA sequencing technology. RSC Adv 2013. [DOI: 10.1039/c3ra41492b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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45
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Pinheiro VB, Loakes D, Holliger P. Synthetic polymers and their potential as genetic materials. Bioessays 2012; 35:113-22. [PMID: 23281109 DOI: 10.1002/bies.201200135] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
DNA and RNA are the only known natural genetic materials. Systematic modification of each of their chemical building blocks (nucleobase, sugar, and phosphate) has enabled the study of the key properties that make those nucleic acids genetic materials. All three moieties contribute to replication and, significantly, all three moieties can be replaced by synthetic analogs without loss of function. Synthetic nucleic acid polymers capable of storing and propagating information not only expand the central dogma, but also highlight that DNA and RNA are not unique chemical solutions for genetic information storage. By considering replication as a question of information transfer, we propose that any polymer that can be replicated could serve as a genetic material.
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Affiliation(s)
- Vitor B Pinheiro
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK.
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46
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Kintses B, Hein C, Mohamed MF, Fischlechner M, Courtois F, Lainé C, Hollfelder F. Picoliter cell lysate assays in microfluidic droplet compartments for directed enzyme evolution. ACTA ACUST UNITED AC 2012; 19:1001-9. [PMID: 22921067 DOI: 10.1016/j.chembiol.2012.06.009] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 11/29/2022]
Abstract
We demonstrate the utility of a microfluidic platform in which water-in-oil droplet compartments serve to miniaturize cell lysate assays by a million-fold for directed enzyme evolution. Screening hydrolytic activities of a promiscuous sulfatase demonstrates that this extreme miniaturization to the single-cell level does not come at a high price in signal quality. Moreover, the quantitative readout delivers a level of precision previously limited to screening methodologies with restricted throughput. The sorting of 3 × 10(7) monodisperse droplets per round of evolution leads to the enrichment of clones with improvements in activity (6-fold) and expression (6-fold). The detection of subtle differences in a larger number of screened clones provides the combination of high sensitivity and high-throughput needed to rescue a stalled directed evolution experiment and make it viable.
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Affiliation(s)
- Balint Kintses
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
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47
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Schmidt M, de Lorenzo V. Synthetic constructs in/for the environment: managing the interplay between natural and engineered Biology. FEBS Lett 2012; 586:2199-206. [PMID: 22710182 PMCID: PMC3396840 DOI: 10.1016/j.febslet.2012.02.022] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 02/14/2012] [Accepted: 02/14/2012] [Indexed: 01/03/2023]
Abstract
The plausible release of deeply engineered or even entirely synthetic/artificial microorganisms raises the issue of their intentional (e.g. bioremediation) or accidental interaction with the Environment. Containment systems designed in the 1980s-1990s for limiting the spread of genetically engineered bacteria and their recombinant traits are still applicable to contemporary Synthetic Biology constructs. Yet, the ease of DNA synthesis and the uncertainty on how non-natural properties and strains could interplay with the existing biological word poses yet again the challenge of designing safe and efficacious firewalls to curtail possible interactions. Such barriers may include xeno-nucleic acids (XNAs) instead of DNA as information-bearing molecules, rewriting the genetic code to make it non-understandable by the existing gene expression machineries, and/or making growth dependent on xenobiotic chemicals.
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Affiliation(s)
| | - Víctor de Lorenzo
- Systems Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), 28049 Cantoblanco-Madrid, Spain
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48
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Ketkar A, Zafar MK, Banerjee S, Marquez VE, Egli M, Eoff RL. A nucleotide-analogue-induced gain of function corrects the error-prone nature of human DNA polymerase iota. J Am Chem Soc 2012; 134:10698-705. [PMID: 22632140 DOI: 10.1021/ja304176q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Y-family DNA polymerases participate in replication stress and DNA damage tolerance mechanisms. The properties that allow these enzymes to copy past bulky adducts or distorted template DNA can result in a greater propensity for them to make mistakes. Of the four human Y-family members, human DNA polymerase iota (hpol ι) is the most error-prone. In the current study, we elucidate the molecular basis for improving the fidelity of hpol ι through use of the fixed-conformation nucleotide North-methanocarba-2'-deoxyadenosine triphosphate (N-MC-dATP). Three crystal structures were solved of hpol ι in complex with DNA containing a template 2'-deoxythymidine (dT) paired with an incoming dNTP or modified nucleotide triphosphate. The ternary complex of hpol ι inserting N-MC-dATP opposite dT reveals that the adenine ring is stabilized in the anti orientation about the pseudo-glycosyl torsion angle, which mimics precisely the mutagenic arrangement of dGTP:dT normally preferred by hpol ι. The stabilized anti conformation occurs without notable contacts from the protein but likely results from constraints imposed by the bicyclo[3.1.0]hexane scaffold of the modified nucleotide. Unmodified dATP and South-MC-dATP each adopt syn glycosyl orientations to form Hoogsteen base pairs with dT. The Hoogsteen orientation exhibits weaker base-stacking interactions and is less catalytically favorable than anti N-MC-dATP. Thus, N-MC-dATP corrects the error-prone nature of hpol ι by preventing the Hoogsteen base-pairing mode normally observed for hpol ι-catalyzed insertion of dATP opposite dT. These results provide a previously unrecognized means of altering the efficiency and the fidelity of a human translesion DNA polymerase.
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Affiliation(s)
- Amit Ketkar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, USA
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49
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Pinheiro VB, Taylor AI, Cozens C, Abramov M, Renders M, Zhang S, Chaput JC, Wengel J, Peak-Chew SY, McLaughlin SH, Herdewijn P, Holliger P. Synthetic genetic polymers capable of heredity and evolution. Science 2012; 336:341-4. [PMID: 22517858 PMCID: PMC3362463 DOI: 10.1126/science.1217622] [Citation(s) in RCA: 500] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Genetic information storage and processing rely on just two polymers, DNA and RNA, yet whether their role reflects evolutionary history or fundamental functional constraints is currently unknown. With the use of polymerase evolution and design, we show that genetic information can be stored in and recovered from six alternative genetic polymers based on simple nucleic acid architectures not found in nature [xeno-nucleic acids (XNAs)]. We also select XNA aptamers, which bind their targets with high affinity and specificity, demonstrating that beyond heredity, specific XNAs have the capacity for Darwinian evolution and folding into defined structures. Thus, heredity and evolution, two hallmarks of life, are not limited to DNA and RNA but are likely to be emergent properties of polymers capable of information storage.
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Affiliation(s)
- Vitor B. Pinheiro
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
| | | | | | - Mikhail Abramov
- REGA Institute, Katholieke Universiteit Leuven, Minderbroederstraat 10, B 3000, Leuven, Belgium
| | - Marleen Renders
- REGA Institute, Katholieke Universiteit Leuven, Minderbroederstraat 10, B 3000, Leuven, Belgium
| | - Su Zhang
- Center for Evolutionary Medicine and Informatics, The Biodesign Institute at Arizona State University, 1001 S. McAllister Avenue, Tempe, AZ 85287-5301, USA
| | - John C. Chaput
- Center for Evolutionary Medicine and Informatics, The Biodesign Institute at Arizona State University, 1001 S. McAllister Avenue, Tempe, AZ 85287-5301, USA
| | - Jesper Wengel
- Nucleic Acid Center, Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Sew-Yeu Peak-Chew
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
| | | | - Piet Herdewijn
- REGA Institute, Katholieke Universiteit Leuven, Minderbroederstraat 10, B 3000, Leuven, Belgium
| | - Philipp Holliger
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
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50
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Lu WC, Ellington AD. In vitro selection of proteins via emulsion compartments. Methods 2012; 60:75-80. [PMID: 22491026 DOI: 10.1016/j.ymeth.2012.03.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 12/23/2011] [Accepted: 03/09/2012] [Indexed: 11/25/2022] Open
Abstract
In vitro compartmentalization (IVC) is a method to generate numerous, small, aqueous compartments (up to 10(10) compartments per ml) by mixing water, surfactants, and oil. The water phase is surrounded by surfactants and an oil phase, and to a first approximation each water-in-oil compartment is like an artificial cell. By introducing single genes into compartments that are competent for transcription and translation, these cell-like compartments can synthesize RNA protein variants in libraries. Screening or selecting for function has in turn led to schemes for the directed evolution of biomolecules. However, IVC selections can cover larger library sizes, and provide greater control over selection conditions and stringencies. The key issue in designing and executing IVC selections is how to couple genotype and phenotype, and in this review we have organized and presented a variety of mechanisms by which proteins and RNA can attach to or amplify their own templates following emulsification and selection.
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Affiliation(s)
- Wei-Cheng Lu
- Institute of Cellular and Molecule Biology, University of Texas at Austin, TX 78712, USA
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