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Kishimoto Y, Fujii A, Nakagawa O, Obika S. Enhanced duplex- and triplex-forming ability and enzymatic resistance of oligodeoxynucleotides modified by a tricyclic thymine derivative. Org Biomol Chem 2021; 19:8063-8074. [PMID: 34494641 DOI: 10.1039/d1ob01462e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We designed and synthesized an artificial nucleic acid, [3-(1,2-dihydro-2-oxobenzo[b][1,8]naphthyridine)]-2'-deoxy-D-ribofuranose (OBN), with a tricyclic structure in a nucleobase as a thymidine analog. Oligodeoxynucleotides (ODNs) containing consecutive OBN displayed improved duplex-forming ability with complementary single-stranded (ss) RNA and triplex-forming ability with double-stranded DNA in comparison with ODNs composed of natural thymidine. OBN-modified ODNs also displayed enhanced enzymatic resistance compared with ODNs with natural thymidine and phosphorothioate modification, respectively, due to the structural steric hindrance of the nucleobase. The fluorescence spectra of OBN-modified ODNs showed sufficient fluorescence intensity with ssDNA and ssRNA, which is an advantageous feature for fluorescence imaging techniques of nucleic acids with longer emission wavelengths than bicyclic thymine (bT).
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Affiliation(s)
- Yuki Kishimoto
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Sciences and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Akane Fujii
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Sciences and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Osamu Nakagawa
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Sciences and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamahoji, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Satoshi Obika
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Sciences and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
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Nakama T, Takezawa Y, Shionoya M. Site-specific polymerase incorporation of consecutive ligand-containing nucleotides for multiple metal-mediated base pairing. Chem Commun (Camb) 2021; 57:1392-1395. [PMID: 33438690 DOI: 10.1039/d0cc07771b] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An enzymatic method has been developed for the synthesis of DNA oligomers containing consecutive artificial ligand-type nucleotides. Three hydroxypyridone ligand-containing nucleotides forming CuII-mediated unnatural base pairs were continuously incorporated at a pre-specified position by a lesion-bypass Dpo4 polymerase. This enzymatic synthesis was applied to the development of a CuII-responsive DNAzyme. Accordingly, this research will open new routes for the construction of metal-responsive DNA architectures that are manipulated by multiple metal-mediated base pairing.
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Affiliation(s)
- Takahiro Nakama
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Takezawa Y, Nakama T, Shionoya M. Enzymatic Synthesis of Cu(II)-Responsive Deoxyribozymes through Polymerase Incorporation of Artificial Ligand-Type Nucleotides. J Am Chem Soc 2019; 141:19342-19350. [PMID: 31731834 DOI: 10.1021/jacs.9b08955] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Metal-mediated artificial base pairs, consisting of ligand-type nucleotides and a bridging metal ion, have shown promise as functional units to develop stimuli-responsive DNA materials. Although a variety of metal-mediated base pairs have been constructed with artificial ligand-type nucleotides and various metal ions, the application of such metal-mediated base pairs has been relatively poorly explored mainly due to the cumbersome chemical synthesis of artificial DNA strands. Herein we report a facile enzymatic method to synthesize DNA strands containing a ligand-type hydroxypyridone (H) nucleotide, which forms a CuII-mediated base pair (H-CuII-H). A two-step primer extension reaction using two commercially available polymerases enabled the incorporation of a H nucleotide at an internal position of oligonucleotides. The polymerase synthesis was subsequently applied to the development of metal-responsive deoxyribozymes (DNAzymes), whose catalytic activity was regulated by the formation of a single H-CuII-H base pair in its stem region. The DNAzyme activity was reversibly switched by the alternate addition and the removal of CuII ions. Furthermore, metal-dependent orthogonal activation of a CuII-responsive H-DNAzyme and a HgII-responsive T-DNAzyme was experimentally demonstrated by utilizing both H-CuII-H as well as widely explored T-HgII-T base pairs. These results suggest that the incorporation of H-CuII-H base pairs would facilitate the rational design of metal-responsive functional DNAs. Accordingly, the facile enzymatic synthesis of artificial ligand-bearing DNAs developed in this study would significantly expand the toolbox of DNA-based supramolecular chemistry and DNA nanotechnology.
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Affiliation(s)
- Yusuke Takezawa
- Department of Chemistry, Graduate School of Science , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-0033 , Japan
| | - Takahiro Nakama
- Department of Chemistry, Graduate School of Science , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-0033 , Japan
| | - Mitsuhiko Shionoya
- Department of Chemistry, Graduate School of Science , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-0033 , Japan
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Whitford CM, Dymek S, Kerkhoff D, März C, Schmidt O, Edich M, Droste J, Pucker B, Rückert C, Kalinowski J. Auxotrophy to Xeno-DNA: an exploration of combinatorial mechanisms for a high-fidelity biosafety system for synthetic biology applications. J Biol Eng 2018; 12:13. [PMID: 30123321 PMCID: PMC6090650 DOI: 10.1186/s13036-018-0105-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/25/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Biosafety is a key aspect in the international Genetically Engineered Machine (iGEM) competition, which offers student teams an amazing opportunity to pursue their own research projects in the field of Synthetic Biology. iGEM projects often involve the creation of genetically engineered bacterial strains. To minimize the risks associated with bacterial release, a variety of biosafety systems were constructed, either to prevent survival of bacteria outside the lab or to hinder horizontal or vertical gene transfer. MAIN BODY Physical containment methods such as bioreactors or microencapsulation are considered the first safety level. Additionally, various systems involving auxotrophies for both natural and synthetic compounds have been utilized by iGEM teams in recent years. Combinatorial systems comprising multiple auxotrophies have been shown to reduced escape frequencies below the detection limit. Furthermore, a number of natural toxin-antitoxin systems can be deployed to kill cells under certain conditions. Additionally, parts of naturally occurring toxin-antitoxin systems can be used for the construction of 'kill switches' controlled by synthetic regulatory modules, allowing control of cell survival. Kill switches prevent cell survival but do not completely degrade nucleic acids. To avoid horizontal gene transfer, multiple mechanisms to cleave nucleic acids can be employed, resulting in 'self-destruction' of cells. Changes in light or temperature conditions are powerful regulators of gene expression and could serve as triggers for kill switches or self-destruction systems. Xenobiology-based containment uses applications of Xeno-DNA, recoded codons and non-canonical amino acids to nullify the genetic information of constructed cells for wild type organisms. A 'minimal genome' approach brings the opportunity to reduce the genome of a cell to only genes necessary for survival under lab conditions. Such cells are unlikely to survive in the natural environment and are thus considered safe hosts. If suitable for the desired application, a shift to cell-free systems based on Xeno-DNA may represent the ultimate biosafety system. CONCLUSION Here we describe different containment approaches in synthetic biology, ranging from auxotrophies to minimal genomes, which can be combined to significantly improve reliability. Since the iGEM competition greatly increases the number of people involved in synthetic biology, we will focus especially on biosafety systems developed and applied in the context of the iGEM competition.
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Affiliation(s)
| | - Saskia Dymek
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Denise Kerkhoff
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Camilla März
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Olga Schmidt
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Maximilian Edich
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Julian Droste
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Boas Pucker
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Present address: Evolution and Diversity, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Christian Rückert
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
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Negi I, Kathuria P, Sharma P, Wetmore SD. How do hydrophobic nucleobases differ from natural DNA nucleobases? Comparison of structural features and duplex properties from QM calculations and MD simulations. Phys Chem Chem Phys 2018; 19:16365-16374. [PMID: 28657627 DOI: 10.1039/c7cp02576a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Computational (DFT and MD simulation) methods are employed to systematically characterize the structural and energetic properties of five hydrophobic nucleobases (FEMO, MMO2, NaM, 5SICS and TPT3) that constitute four unnatural base pairs (FEMO:5SICS, MMO2:5SICS, NaM:5SICS and TPT3:NaM). These hydrophobic bases have been recently shown to be replicated when present between natural bases in DNA duplexes, with the highest replication fidelity and efficiency occuring for the TPT3:NaM pair. Our QM calculations suggest that the preferred (anti) glycosidic orientations of nucleosides containing hydrophobic bases are similar to the natural DNA nucleosides despite differences in their chemical structures. However, due to the inability to form interbase hydrogen bonds, hydrophobic base pairs intrinsically prefer nonplanar, distorted geometries, many of which are stabilized through π-π stacking interactions. Furthermore, the intrinsic stacking potential between a hydrophobic and a natural base is similar to that between two natural bases, indicating that the strength of stacking interactions in DNA duplexes containing hydrophobic bases is likely comparable to natural DNA. However, in contrast to the isolated base-pair geometries, our MD simulations suggest that the hydrophobic base pairs adopt variable geometries within DNA, which range from stacked (5SICS:FEMO) to nearly planar (5SICS:NaM and SICS:MMO2) to planar (TPT3:NaM). As a result, the duplex structural features at the site of modification depend on the identity of the hydrophobic base pair, where the TPT3:NaM pair causes the least structural changes compared to natural DNA. Overall, the structural insight obtained from our calculations on DNA containing hydrophobic base pairs explains the experimentally-observed higher fidelity and efficiency during replication of TPT3:NaM compared to other hydrophobic nucleobase pairs. By providing valuable structural information that explains the intrinsic and duplex properties of this class of unnatural nucleobases, the present work may aid the future design of improved hydrophobic analogues.
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Affiliation(s)
- Indu Negi
- Computational Biochemistry Laboratory, Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh, 160014, India.
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Wang R, Jin C, Zhu X, Zhou L, Xuan W, Liu Y, Liu Q, Tan W. Artificial Base zT as Functional "Element" for Constructing Photoresponsive DNA Nanomolecules. J Am Chem Soc 2017; 139:9104-9107. [PMID: 28585836 PMCID: PMC5877792 DOI: 10.1021/jacs.7b02865] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In contrast to small molecules, DNA and RNA macromolecules can be accurately formulated with base "elements" abbreviated as A, T, U, C, and G. However, the development of functionally artificial bases can result in the generation of new biomaterials with unique properties and applications. Therefore, we herein report the design and synthesis of a photoresponsive base as a new functional or molecular "element" for constructing DNA nanomolecules. The new base is made by fusion of an azobenzene with a natural T base (zT). zT, a new molecular element, is not only the most size-expanded T analogue but also a photoresponsive base capable of specific self-assembly through hydrogen bonding. Our results showed that stable and selective self-assembly of double-stranded DNAs occurred through zT-A base pairing, but it could still be efficiently dissociated by light irradiation. The photoresponsive DNA bases will provide the versatility required for constructing desired DNA nanomolecules and nanodevices.
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Affiliation(s)
- Ruowen Wang
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Cheng Jin
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Xiaoyan Zhu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Liyi Zhou
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Wenjing Xuan
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Yuan Liu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Qiaoling Liu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Weihong Tan
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
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7
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Bag SS, Das SK. Design, Synthesis and Photophysical Property of a Doubly Widened Fused-Triazolyl-Phenanthrene Unnatural Nucleoside. ChemistrySelect 2017. [DOI: 10.1002/slct.201700392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Subhendu Sekhar Bag
- Bioorganic Chemistry Laboratory; Department of Chemistry; Indian Institute of Technology Guwahati, North Guwhati-; 781039 Assam India
| | - Suman Kalyan Das
- Bioorganic Chemistry Laboratory; Department of Chemistry; Indian Institute of Technology Guwahati, North Guwhati-; 781039 Assam India
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8
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Albrecht L, Wilson KA, Wetmore SD. Computational Evaluation of Nucleotide Insertion Opposite Expanded and Widened DNA by the Translesion Synthesis Polymerase Dpo4. Molecules 2016; 21:molecules21070822. [PMID: 27347908 PMCID: PMC6273265 DOI: 10.3390/molecules21070822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/08/2016] [Accepted: 06/14/2016] [Indexed: 11/25/2022] Open
Abstract
Expanded (x) and widened (y) deoxyribose nucleic acids (DNA) have an extra benzene ring incorporated either horizontally (xDNA) or vertically (yDNA) between a natural pyrimidine base and the deoxyribose, or between the 5- and 6-membered rings of a natural purine. Far-reaching applications for (x,y)DNA include nucleic acid probes and extending the natural genetic code. Since modified nucleobases must encode information that can be passed to the next generation in order to be a useful extension of the genetic code, the ability of translesion (bypass) polymerases to replicate modified bases is an active area of research. The common model bypass polymerase DNA polymerase IV (Dpo4) has been previously shown to successfully replicate and extend past a single modified nucleobase on a template DNA strand. In the current study, molecular dynamics (MD) simulations are used to evaluate the accommodation of expanded/widened nucleobases in the Dpo4 active site, providing the first structural information on the replication of (x,y)DNA. Our results indicate that the Dpo4 catalytic (palm) domain is not significantly impacted by the (x,y)DNA bases. Instead, the template strand is displaced to accommodate the increased C1’–C1’ base-pair distance. The structural insights unveiled in the present work not only increase our fundamental understanding of Dpo4 replication, but also reveal the process by which Dpo4 replicates (x,y)DNA, and thereby will contribute to the optimization of high fidelity and efficient polymerases for the replication of modified nucleobases.
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Affiliation(s)
- Laura Albrecht
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge Alberta, AB T1K 3M4, Canada.
| | - Katie A Wilson
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge Alberta, AB T1K 3M4, Canada.
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge Alberta, AB T1K 3M4, Canada.
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Aparna P, Varughese M, Varghese MK, Haris P, Sudarsanakumar C. Conformational features of benzo-homologated yDNA duplexes by molecular dynamics simulation. Biopolymers 2015; 105:55-64. [PMID: 26385415 DOI: 10.1002/bip.22743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 09/08/2015] [Accepted: 09/10/2015] [Indexed: 11/07/2022]
Abstract
yDNA is a base-modified nucleic acid duplex containing size-expanded nucleobases. Base-modified nucleic acids could expand the genetic alphabet and thereby enhance the functional potential of DNA. Unrestrained 100 ns MD simulations were performed in explicit solvent on the yDNA NMR sequence [5'(yA T yA yA T yA T T yA T)2 ] and two modeled yDNA duplexes, [5'(yC yC G yC yC G G yC G G)2 ] and [(yT5' G yT A yC yG C yA yG T3')•(yA5' C T C yG C G yT A yC A3')]. The force field parameters for the yDNA bases were derived in consistent with the well-established AMBER force field. Our results show that DNA backbone can withstand the stretched size of the bases retaining the Watson-Crick base pairing in the duplexes. The duplexes retained their double helical structure throughout the simulations accommodating the strain due to expanded bases in the backbone torsion angles, sugar pucker and helical parameters. The effect of the benzo-expansion is clearly reflected in the extended C1'-C1' distances and enlarged groove widths. The size expanded base modification leads to reduction in base pair twist resulting in larger overlapping area between the stacked bases, enhancing inter and intra strand stacking interactions in yDNA in comparison with BDNA. This geometry could favour enhanced interactions with the groove binders and DNA binding proteins., 2016. © 2015 Wiley Periodicals, Inc. Biopolymers 105: 55-64, 2016.
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Affiliation(s)
- P Aparna
- School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
| | - Mary Varughese
- School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
| | - Mathew K Varghese
- School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India.,Department of Physics, Pavanatma College, Murickassery, Kerala, 685604, India
| | - P Haris
- School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
| | - C Sudarsanakumar
- School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, 686560, India.,Center for High Performance Computing, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
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Rezzonico F. Nanopore-based instruments as biosensors for future planetary missions. ASTROBIOLOGY 2014; 14:344-351. [PMID: 24684166 DOI: 10.1089/ast.2013.1120] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Data from automated orbiters and landers have dashed humankind's hopes of finding complex life-forms elsewhere in the Solar System. The focus of exobiological research was thus forced to shift from the detection of life through simple visual imaging to complex biochemical experiments aimed at the detection of microbial activity. Searching for biosignatures over interplanetary distances is a formidable task and poses the dilemma of what are the proper experiments that can be performed on-site to maximize the chances of success if extraterrestrial life is present but not evident. Despite their astonishing morphological diversity, all known organisms on Earth share the same basic molecular architecture; thus the vast majority of our detection and identification techniques are b(i)ased on Terran biochemistry. There is, however, a distinct possibility that life may have emerged elsewhere by using other molecular building blocks, a fact that is likely to make the outcome of most of the current molecular biological and biochemical life-detection protocols difficult to interpret if not completely ineffective. Nanopore-based sensing devices allow the analysis of single molecules, including the sequence of informational biopolymers such as DNA or RNA, by measuring current changes across an electrically resistant membrane when the analyte flows through an embedded transmembrane protein or a solid-state nanopore. Under certain basic assumptions about their physical properties, this technology has the potential to discriminate and possibly analyze biopolymers, in particular genetic information carriers, without prior detailed knowledge of their fundamental chemistry and is sufficiently portable to be used for automated analysis in planetary exploration, all of which makes it the ideal candidate for the search for life signatures in remote watery environments such as Mars, Europa, or Enceladus.
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Affiliation(s)
- Fabio Rezzonico
- Research group Environmental Genomics and Systems Biology, Zurich University for Applied Sciences (ZHAW) , Wädenswil, Switzerland
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Winnacker M, Kool ET. Artificial genetic sets composed of size-expanded base pairs. Angew Chem Int Ed Engl 2013; 52:12498-508. [PMID: 24249550 PMCID: PMC5497059 DOI: 10.1002/anie.201305267] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Indexed: 12/23/2022]
Abstract
We describe in this Minireview the synthesis, properties, and applications of artificial genetic sets built from base pairs that are larger than the natural Watson-Crick architecture. Such designed systems are being explored by several research groups to investigate basic chemical questions regarding the functions of the genetic information storage systems and thus of the origin and evolution of life. For example, is the terrestrial DNA structure the only viable one, or can other architectures function as well? Working outside the constraints of purine-pyrimidine geometry provides more chemical flexibility in design, and the added size confers useful properties such as high binding affinity and helix stability as well as fluorescence. These features are useful for the investigation of fundamental biochemical questions as well as in the development of new biotechnological, biomedical, and nanostructural tools and methods.
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Affiliation(s)
- Malte Winnacker
- Department of Chemistry, Stanford University, Stanford, CA 94305 (USA)
| | - Eric T. Kool
- Department of Chemistry, Stanford University, Stanford, CA 94305 (USA)
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12
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Winnacker M, Kool ET. Künstliche genetische Systeme bestehend aus vergrößerten Basenpaaren. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305267] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Sharma P, Lait LA, Wetmore SD. yDNA versus yyDNA pyrimidines: computational analysis of the effects of unidirectional ring expansion on the preferred sugar-base orientation, hydrogen-bonding interactions and stacking abilities. Phys Chem Chem Phys 2013; 15:2435-48. [PMID: 23303174 DOI: 10.1039/c2cp43910g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The properties of natural, y- and yy-pyrimidines are compared using computational (B3LYP, MP2) methods. Ring expansion upon incorporation of benzene or naphthalene into the natural pyrimidines affects the preferred orientation of the base about the glycosidic bond in the corresponding nucleoside to a similar extent. Specifically, although the natural pyrimidines preferentially adopt the anti orientation with respect to the 2'-deoxyribose moiety, the expanded analogues will likely display (anti/syn) conformational heterogeneity, which may lead to alternate hydrogen-bonding modes in double-stranded duplexes. Nevertheless, the A:T Watson-Crick hydrogen-bond strengths do not significantly change upon base expansion, while the G:C interaction energy is slightly strengthened upon incorporation of either expanded pyrimidine. The largest effect of base expansion occurs in the stacking energies. Specifically, the maximum (most negative) stacking energies in isolated dimers formed by aligning the nucleobase centers of mass can be increased up to 45% by inclusion of a single y-pyrimidine and up to 55% by consideration of a yy-pyrimidine. Similar increases in the stacking interactions are found when a simplified duplex model composed of two stacked (hydrogen-bonded) base pairs is considered, where both the intrastrand and interstrand stacking interactions can be increased and the effects are more pronounced for the yy-pyrimidines. Moreover, the total stability (sum of all hydrogen-bonding and stacking interactions) is greater for duplexes containing expanded yy-pyrimidines compared to y-pyrimidines, which is mainly due to enhanced stacking interactions. Thus, our calculations suggest that multiple unidirectional increases in the size of the nucleobase spacer can continuously enhance the stability of expanded duplexes.
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Affiliation(s)
- Purshotam Sharma
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
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Pinheiro VB, Holliger P. The XNA world: progress towards replication and evolution of synthetic genetic polymers. Curr Opin Chem Biol 2012; 16:245-52. [PMID: 22704981 DOI: 10.1016/j.cbpa.2012.05.198] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 05/16/2012] [Accepted: 05/21/2012] [Indexed: 01/25/2023]
Abstract
Life's diversity is built on the wide range of properties and functions that can be encoded in natural biopolymers such as polypeptides and nucleic acids. However, despite their versatility, the range of chemical functionalities is limited, particularly in the case of nucleic acids. Chemical modification of nucleic acids can greatly increase their functional diversity but access to the full phenotypic potential of such polymers requires a system of replication. Here we review progress in the chemical and enzymatic synthesis, replication and evolution of unnatural nucleic acid polymers, which promises to enable the exploration of a vast sequence space not accessible to nature and deliver ligands, catalysts and materials based on this new class of biopolymers.
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Affiliation(s)
- Vitor B Pinheiro
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
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Affiliation(s)
- Yin Nah Teo
- Department of Chemistry, Stanford University, California 94305, United States
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