1
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Zhang Y, Takaki Y, Yoshida-Takashima Y, Hiraoka S, Kurosawa K, Nunoura T, Takai K. A sequential one-pot approach for rapid and convenient characterization of putative restriction-modification systems. mSystems 2023; 8:e0081723. [PMID: 37843256 PMCID: PMC10734518 DOI: 10.1128/msystems.00817-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023] Open
Abstract
IMPORTANCE The elucidation of the molecular basis of virus-host coevolutionary interactions is boosted with state-of-the-art sequencing technologies. However, the sequence-only information is often insufficient to output a conclusive argument without biochemical characterizations. We proposed a 1-day and one-pot approach to confirm the exact function of putative restriction-modification (R-M) genes that presumably mediate microbial coevolution. The experiments mainly focused on a series of putative R-M enzymes from a deep-sea virus and its host bacterium. The results quickly unveiled unambiguous substrate specificities, superior catalytic performance, and unique sequence preferences for two new restriction enzymes (capable of cleaving DNA) and two new methyltransferases (capable of modifying DNA with methyl groups). The reality of the functional R-M system reinforced a model of mutually beneficial interactions with the virus in the deep-sea microbial ecosystem. The cell culture-independent approach also holds great potential for exploring novel and biotechnologically significant R-M enzymes from microbial dark matter.
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Affiliation(s)
- Yi Zhang
- SUGAR Program, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Yoshihiro Takaki
- SUGAR Program, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Yukari Yoshida-Takashima
- SUGAR Program, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Satoshi Hiraoka
- Research Center for Bioscience and Nanoscience (CeBN), MRU, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Kanako Kurosawa
- SUGAR Program, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Takuro Nunoura
- Research Center for Bioscience and Nanoscience (CeBN), MRU, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Ken Takai
- SUGAR Program, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
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2
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Ouyang Y, Dong J, Willner I. Dynamic DNA Networks-Guided Directional and Orthogonal Transient Biocatalytic Cascades. J Am Chem Soc 2023; 145:22135-22149. [PMID: 37773962 PMCID: PMC10571085 DOI: 10.1021/jacs.3c08020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Indexed: 10/01/2023]
Abstract
DNA frameworks, consisting of constitutional dynamic networks (CDNs) undergoing fuel-driven reconfiguration, are coupled to a dissipative reaction module that triggers the reconfigured CDNs into a transient intermediate CDNs recovering the parent CDN state. Biocatalytic cascades consisting of the glucose oxidase (GOx)/horseradish peroxidase (HRP) couple or the lactate dehydrogenase (LDH)/nicotinamide adenine dinucleotide (NAD+) couple are tethered to the constituents of two different CDNs, allowing the CDNs-guided operation of the spatially confined GOx/HRP or LDH/NAD+ biocatalytic cascades. By applying two different fuel triggers, the directional transient CDN-guided upregulation/downregulation of the two biocatalytic cascades are demonstrated. By mixing the GOx/HRP-biocatalyst-modified CDN with the LDH/NAD+-biocatalyst-functionalized CDN, a composite CDN is assembled. Triggering the composite CDN with two different fuel strands results in orthogonal transient upregulation of the GOx/HRP cascade and transient downregulation of the LDH/NAD+ cascade or vice versa. The transient CDNs-guided biocatalytic cascades are computationally simulated by kinetic models, and the computational analyses allow the prediction of the performance of transient biocatalytic cascades under different auxiliary conditions. The concept of orthogonally triggered temporal, transient, biocatalytic cascades by means of CDN frameworks is applied to design an orthogonally operating CDN for the temporal upregulated or downregulated transient thrombin-induced coagulation of fibrinogen to fibrin.
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Affiliation(s)
- Yu Ouyang
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Jiantong Dong
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Itamar Willner
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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3
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Wang Y, Wang Y, Chen Y, Yan Q, Lin A. Research progress in mitochondrial gene editing technology. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:460-472. [PMID: 37643980 PMCID: PMC10495247 DOI: 10.3724/zdxbyxb-2023-0129] [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: 03/17/2023] [Accepted: 07/20/2023] [Indexed: 08/12/2023]
Abstract
Mitochondrial DNA (mtDNA) mutations result in a variety of genetic diseases. As an emerging therapeutic method, mtDNA editing technology recognizes targets more based on the protein and less on the nucleic acid. Although the protein recognition type mtDNA editing technology represented by zinc finger nuclease technology, transcription activator like effector nuclease technology and base editing technology has made some progress, the disadvantages of complex recognition sequence design hinder further popularization. Gene editing based on nucleic acid recognition by the CRISPR system shows superiority due to the simple structure, easy design and modification. However, the lack of effective means to deliver nucleic acids into mitochondria limits application in the field of mtDNA editing. With the advances in the study of endogenous and exogenous import pathways and the deepening understanding of DNA repair mechanisms, growing evidence shows the feasibility of nucleic acid delivery and the broad application prospects of nucleic acid recognition type mtDNA editing technology. Based on the classification of recognition elements, this article summarizes the current principles and development of mitochondrial gene editing technology, and discusses its application prospects.
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Affiliation(s)
- Yichen Wang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
- Zhejiang University Cancer Center, Hangzhou 310058, China.
| | - Ying Wang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Zhejiang University Cancer Center, Hangzhou 310058, China
| | - Yu Chen
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Zhejiang University Cancer Center, Hangzhou 310058, China
| | - Qingfeng Yan
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Aifu Lin
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
- Zhejiang University Cancer Center, Hangzhou 310058, China.
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Center for RNA Medicine, International Institutes of Medicine, Zhejiang University, Jinhua 322000, Zhejiang Province, China.
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4
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Egido JE, Costa AR, Aparicio-Maldonado C, Haas PJ, Brouns SJJ. Mechanisms and clinical importance of bacteriophage resistance. FEMS Microbiol Rev 2021; 46:6374866. [PMID: 34558600 PMCID: PMC8829019 DOI: 10.1093/femsre/fuab048] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/15/2021] [Indexed: 12/24/2022] Open
Abstract
We are in the midst of a golden age of uncovering defense systems against bacteriophages. Apart from the fundamental interest in these defense systems, and revolutionary applications that have been derived from them (e.g. CRISPR-Cas9 and restriction endonucleases), it is unknown how defense systems contribute to resistance formation against bacteriophages in clinical settings. Bacteriophages are now being reconsidered as therapeutic agents against bacterial infections due the emergence of multidrug resistance. However, bacteriophage resistance through defense systems and other means could hinder the development of successful phage-based therapies. Here, we review the current state of the field of bacteriophage defense, highlight the relevance of bacteriophage defense for potential clinical use of bacteriophages as therapeutic agents and suggest new directions of research.
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Affiliation(s)
- Julia E Egido
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, Netherlands
| | - Ana Rita Costa
- Department of Bionanoscience, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands.,Fagenbank, Delft, Netherlands
| | - Cristian Aparicio-Maldonado
- Department of Bionanoscience, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands
| | - Pieter-Jan Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands.,Fagenbank, Delft, Netherlands
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5
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Szewczuk M, Boguszewska K, Kaźmierczak-Barańska J, Karwowski BT. The Influence of 5' R and 5' S cdA and cdG on the Activity of BsmAI and SspI Restriction Enzymes. Molecules 2021; 26:molecules26123750. [PMID: 34205449 PMCID: PMC8234751 DOI: 10.3390/molecules26123750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 01/03/2023] Open
Abstract
Restriction endonucleases (REs) are intra-bacterial scissors that are considered tools in the fight against foreign genetic material. SspI and BsmAI, examined in this study, cleave dsDNA at their site of recognition or within a short distance of it. Both enzymes are representatives of type II REs, which have played an extremely important role in research on the genetics of organisms and molecular biology. Therefore, the study of agents affecting their activity has become highly important. Ionizing radiation may damage basic cellular mechanisms by inducing lesions in the genome, with 5',8-cyclo-2'-deoxypurines (cdPus) as a model example. Since cdPus may become components of clustered DNA lesions (CDLs), which are unfavorable for DNA repair pathways, their impact on other cellular mechanisms is worthy of attention. This study investigated the influence of cdPus on the elements of the bacterial restriction-modification system. In this study, it was shown that cdPus present in DNA affect the activity of REs. SspI was blocked by any cdPu lesion present at the enzyme's recognition site. When lesions were placed near the recognition sequence, the SspI was inhibited up to 46%. Moreover, (5'S)-5',8-cyclo-2'-deoxyadenosine (ScdA) present in the oligonucleotide sequence lowered BsmAI activity more than (5'R)-5',8-cyclo-2'-deoxyadenosine (RcdA). Interestingly, in the case of 5',8-cyclo-2'-deoxyguanosine (cdG), both 5'S and 5'R diastereomers inhibited BsmAI activity (up to 55% more than cdA). The inhibition was weaker when cdG was present at the recognition site rather than the cleavage site.
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6
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Schneider TD, Jejjala V. Restriction enzymes use a 24 dimensional coding space to recognize 6 base long DNA sequences. PLoS One 2019; 14:e0222419. [PMID: 31671158 PMCID: PMC6822723 DOI: 10.1371/journal.pone.0222419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/29/2019] [Indexed: 11/19/2022] Open
Abstract
Restriction enzymes recognize and bind to specific sequences on invading bacteriophage DNA. Like a key in a lock, these proteins require many contacts to specify the correct DNA sequence. Using information theory we develop an equation that defines the number of independent contacts, which is the dimensionality of the binding. We show that EcoRI, which binds to the sequence GAATTC, functions in 24 dimensions. Information theory represents messages as spheres in high dimensional spaces. Better sphere packing leads to better communications systems. The densest known packing of hyperspheres occurs on the Leech lattice in 24 dimensions. We suggest that the single protein EcoRI molecule employs a Leech lattice in its operation. Optimizing density of sphere packing explains why 6 base restriction enzymes are so common.
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Affiliation(s)
- Thomas D. Schneider
- National Institutes of Health, National Cancer Institute, Center for Cancer Research, RNA Biology Laboratory, Frederick, Maryland, United States of America
| | - Vishnu Jejjala
- Mandelstam Institute for Theoretical Physics, School of Physics, NITheP, and CoE-MaSS, University of the Witwatersrand, Johannesburg, South Africa
- David Rittenhouse Laboratory, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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7
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Screening substrate-binding positions by rolling circle amplification suggesting a binding model of Nt.BstNBI. Biochem J 2019; 476:1483-1496. [PMID: 31064800 DOI: 10.1042/bcj20190167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/29/2019] [Accepted: 05/04/2019] [Indexed: 02/05/2023]
Abstract
Nicking endonucleases (NEs) become increasingly attractive for their promising applications in isothermal amplification. Unfortunately, in comparison with their applications, their catalytic mechanism studies have relatively lagged behind due to a paucity of crystal structure information. Nt.BstNBI is one of those widely used NEs. However, many aspects of its catalytic mechanism still remained to be explored. Herein, we employed only rolling circle amplification (RCA) assay as a major analytic tool and succeeded in identifying the potential binding positions and regions of the DNA substrate based on locked nucleic acid modification, DNA duplex length of substrate, and substrate mismatch designs. Based on these data, we, for the first time, revealed that Nt.BstNBI was likely to recognize six adjacent positions of the recognition sequence (G1rt, A2rt, G3rt, A2rb, C3rb, and T4rb) in the major groove and hold three positions of the cleavage sequence (N3ct, N4ct, and N7cb) in the minor groove of DNA duplex for nicking. Moreover, this work also demonstrated the unexpected efficiency of RCA to study the macromolecular interaction for certain kind of nucleases in an easy and high-throughput way.
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8
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Di Felice F, Micheli G, Camilloni G. Restriction enzymes and their use in molecular biology: An overview. J Biosci 2019. [DOI: 10.1007/s12038-019-9856-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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9
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Shahbazi MA, Bauleth-Ramos T, Santos HA. DNA Hydrogel Assemblies: Bridging Synthesis Principles to Biomedical Applications. ADVANCED THERAPEUTICS 2018. [DOI: 10.1002/adtp.201800042] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Mohammad-Ali Shahbazi
- Drug Research Program; Division of Pharmaceutical Chemistry and Technology; Faculty of Pharmacy; FI-00014 University of Helsinki; Helsinki Finland
- Department of Micro- and Nanotechnology; Technical University of Denmark; Ørsteds Plads DK-2800 Kgs Lyngby Denmark
- Department of Pharmaceutical Nanotechnology; School of Pharmacy; Zanjan University of Medical Sciences; 56184-45139 Zanjan Iran
| | - Tomás Bauleth-Ramos
- Drug Research Program; Division of Pharmaceutical Chemistry and Technology; Faculty of Pharmacy; FI-00014 University of Helsinki; Helsinki Finland
- Instituto de Investigação e Inovação em Saúde; University of Porto; Rua Alfredo Allen 208 4200-135 Porto Portugal
- Instituto de Engenharia Biomédica; University of Porto; Rua Alfredo Allen 208 4200-135 Porto Portugal
- Instituto Ciências Biomédicas Abel Salazar; University of Porto; Rua Jorge Viterbo 228 4150-180 Porto Portugal
| | - Hélder A. Santos
- Drug Research Program; Division of Pharmaceutical Chemistry and Technology; Faculty of Pharmacy; FI-00014 University of Helsinki; Helsinki Finland
- Helsinki Institute of Life Science; FI-00014 University of Helsinki; Helsinki Finland
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10
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Abstract
Restriction enzymes are essential tools for recombinant DNA technology that have revolutionized modern biological research. However, they have limited sequence specificity and availability. Here we report a Pyrococcus furiosus Argonaute (PfAgo) based platform for generating artificial restriction enzymes (AREs) capable of recognizing and cleaving DNA sequences at virtually any arbitrary site and generating defined sticky ends of varying length. Short DNA guides are used to direct PfAgo to target sites for cleavage at high temperatures (>87 °C) followed by reannealing of the cleaved single stranded DNAs. We used this platform to generate over 18 AREs for DNA fingerprinting and molecular cloning of PCR-amplified or genomic DNAs. These AREs work as efficiently as their naturally occurring counterparts, and some of them even do not have any naturally occurring counterparts, demonstrating easy programmability, generality, versatility, and high efficiency for this new technology.
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Affiliation(s)
- Behnam Enghiad
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, Department of Chemistry, Department of Biochemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Huimin Zhao
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, Department of Chemistry, Department of Biochemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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11
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Kahn JS, Hu Y, Willner I. Stimuli-Responsive DNA-Based Hydrogels: From Basic Principles to Applications. Acc Chem Res 2017; 50:680-690. [PMID: 28248486 DOI: 10.1021/acs.accounts.6b00542] [Citation(s) in RCA: 274] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The base sequence of nucleic acids encodes structural and functional information into the DNA biopolymer. External stimuli such as metal ions, pH, light, or added nucleic acid fuel strands provide triggers to reversibly switch nucleic acid structures such as metal-ion-bridged duplexes, i-motifs, triplex nucleic acids, G-quadruplexes, or programmed double-stranded hybrids of oligonucleotides (DNA). The signal-triggered oligonucleotide structures have been broadly applied to develop switchable DNA nanostructures and DNA machines, and these stimuli-responsive assemblies provide functional scaffolds for the rapidly developing area of DNA nanotechnology. Stimuli-responsive hydrogels undergoing signal-triggered hydrogel-to-solution transitions or signal-controlled stiffness changes attract substantial interest as functional matrices for controlled drug delivery, materials exhibiting switchable mechanical properties, acting as valves or actuators, and "smart" materials for sensing and information processing. The integration of stimuli-responsive oligonucleotides with hydrogel-forming polymers provides versatile means to exploit the functional information encoded in the nucleic acid sequences to yield stimuli-responsive hydrogels exhibiting switchable physical, structural, and chemical properties. Stimuli-responsive DNA-based nucleic acid structures are integrated in acrylamide polymer chains and reversible, switchable hydrogel-to-solution transitions of the systems are demonstrated by applying external triggers, such as metal ions, pH-responsive strands, G-quadruplex, and appropriate counter triggers that bridge and dissociate the polymer chains. By combining stimuli-responsive nucleic acid bridges with thermosensitive poly(N-isopropylacrylamide) (pNIPAM) chains, systems undergoing reversible solution ↔ hydrogel ↔ solid transitions are demonstrated. Specifically, by bridging acrylamide polymer chains by two nucleic acid functionalities, where one type of bridging unit provides a stimuli-responsive element and the second unit acts as internal "bridging memory", shape-memory hydrogels undergoing reversible and switchable transitions between shaped hydrogels and shapeless quasi-liquid states are demonstrated. By using stimuli-responsive hydrogel cross-linking units that can assemble the bridging units by two different input signals, the orthogonally-triggered functions of the shape-memory were shown. Furthermore, a versatile approach to assemble stimuli-responsive DNA-based acrylamide hydrogel films on surfaces is presented. The method involves the activation of the hybridization chain-reaction (HCR) by a surface-confined promoter strand, in the presence of acrylamide chains modified with two DNA hairpin structures and appropriate stimuli-responsive tethers. The resulting hydrogel-modified surfaces revealed switchable stiffness properties and signal-triggered catalytic functions. By applying the method to assemble the hydrogel microparticles, substrate-loaded, stimuli-responsive microcapsules are prepared. The signal-triggered DNA-based hydrogel microcapsules are applied as drug carriers for controlled release. The different potential applications and future perspectives of stimuli responsive hydrogels are discussed. Specifically, the use of these smart materials and assemblies as carriers for controlled drug release and as shape-memory matrices for information storage and inscription and the use of surface-confined stimuli-responsive hydrogels, exhibiting switchable stiffness properties, for catalysis and controlled growth of cells are discussed.
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Affiliation(s)
- Jason S. Kahn
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yuwei Hu
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Itamar Willner
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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12
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Johnson PM, Gucinski GC, Garza-Sánchez F, Wong T, Hung LW, Hayes CS, Goulding CW. Functional Diversity of Cytotoxic tRNase/Immunity Protein Complexes from Burkholderia pseudomallei. J Biol Chem 2016; 291:19387-400. [PMID: 27445337 DOI: 10.1074/jbc.m116.736074] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Indexed: 12/23/2022] Open
Abstract
Contact-dependent growth inhibition (CDI) is a widespread mechanism of inter-bacterial competition. CDI(+) bacteria deploy large CdiA effector proteins, which carry variable C-terminal toxin domains (CdiA-CT). CDI(+) cells also produce CdiI immunity proteins that specifically neutralize cognate CdiA-CT toxins to prevent auto-inhibition. Here, we present the crystal structure of the CdiA-CT/CdiI(E479) toxin/immunity protein complex from Burkholderia pseudomallei isolate E479. The CdiA-CT(E479) tRNase domain contains a core α/β-fold that is characteristic of PD(D/E)XK superfamily nucleases. Unexpectedly, the closest structural homolog of CdiA-CT(E479) is another CDI toxin domain from B. pseudomallei 1026b. Although unrelated in sequence, the two B. pseudomallei nuclease domains share similar folds and active-site architectures. By contrast, the CdiI(E479) and CdiI(1026b) immunity proteins share no significant sequence or structural homology. CdiA-CT(E479) and CdiA-CT(1026b) are both tRNases; however, each nuclease cleaves tRNA at a distinct position. We used a molecular docking approach to model each toxin bound to tRNA substrate. The resulting models fit into electron density envelopes generated by small-angle x-ray scattering analysis of catalytically inactive toxin domains bound stably to tRNA. CdiA-CT(E479) is the third CDI toxin found to have structural homology to the PD(D/E)XK superfamily. We propose that CDI systems exploit the inherent sequence variability and active-site plasticity of PD(D/E)XK nucleases to generate toxin diversity. These findings raise the possibility that many other uncharacterized CDI toxins may belong to the PD(D/E)XK superfamily.
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Affiliation(s)
| | | | - Fernando Garza-Sánchez
- Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California 93106-9625, and
| | - Timothy Wong
- From the Departments of Molecular Biology and Biochemistry and
| | - Li-Wei Hung
- the Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - Christopher S Hayes
- the Biomolecular Science and Engineering Program and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California 93106-9625, and
| | - Celia W Goulding
- From the Departments of Molecular Biology and Biochemistry and Pharmaceutical Sciences, University of California at Irvine, Irvine, California 92697,
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13
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Production of dumbbell probe through hairpin cleavage-ligation and increasing RCA sensitivity and specificity by circle to circle amplification. Sci Rep 2016; 6:29229. [PMID: 27385060 PMCID: PMC4935871 DOI: 10.1038/srep29229] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/16/2016] [Indexed: 11/23/2022] Open
Abstract
Dumbbell probe (DP) attracts increasing interests in rolling circle amplification (RCA). A universal DP production method through cleavage-ligation of hairpin was proposed and optimized. The production is characterized by restriction endonuclease (RE)-induced cleavage ends ligation. It has the advantage of phosphorylation-free, splint-free and purification-free. To optimize designing, we found that the position of RE cleavage sequence in the stem and the primer position in the loop affected the formation and amplification of DP obviously. Both sticky and blunt ends cleaved by RE produce DP efficiently. Moreover, we introduced this DP into circle to circle (C2C) RCA based on the same cleavage-ligation principle, and acquired high sensitivity. By combining a two-ligation design and the C2C strategy, specificity for detecting let-7 family members was increased extremely. Furthermore, coreaction of different steps facilitated convenient formation and amplification process of DP.
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14
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Walsh G. Additional Industrial Enzymes. Proteins 2015. [DOI: 10.1002/9781119117599.ch13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Bank C, Hietpas RT, Jensen JD, Bolon DNA. A systematic survey of an intragenic epistatic landscape. Mol Biol Evol 2014; 32:229-38. [PMID: 25371431 DOI: 10.1093/molbev/msu301] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mutations are the source of evolutionary variation. The interactions of multiple mutations can have important effects on fitness and evolutionary trajectories. We have recently described the distribution of fitness effects of all single mutations for a nine-amino-acid region of yeast Hsp90 (Hsp82) implicated in substrate binding. Here, we report and discuss the distribution of intragenic epistatic effects within this region in seven Hsp90 point mutant backgrounds of neutral to slightly deleterious effect, resulting in an analysis of more than 1,000 double mutants. We find negative epistasis between substitutions to be common, and positive epistasis to be rare--resulting in a pattern that indicates a drastic change in the distribution of fitness effects one step away from the wild type. This can be well explained by a concave relationship between phenotype and genotype (i.e., a concave shape of the local fitness landscape), suggesting mutational robustness intrinsic to the local sequence space. Structural analyses indicate that, in this region, epistatic effects are most pronounced when a solvent-inaccessible position is involved in the interaction. In contrast, all 18 observations of positive epistasis involved at least one mutation at a solvent-exposed position. By combining the analysis of evolutionary and biophysical properties of an epistatic landscape, these results contribute to a more detailed understanding of the complexity of protein evolution.
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Affiliation(s)
- Claudia Bank
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Ryan T Hietpas
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Jeffrey D Jensen
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Daniel N A Bolon
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
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16
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Wang F, Lu CH, Willner I. From cascaded catalytic nucleic acids to enzyme-DNA nanostructures: controlling reactivity, sensing, logic operations, and assembly of complex structures. Chem Rev 2014; 114:2881-941. [PMID: 24576227 DOI: 10.1021/cr400354z] [Citation(s) in RCA: 494] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fuan Wang
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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Orbach R, Guo W, Wang F, Lioubashevski O, Willner I. Self-assembly of luminescent Ag nanocluster-functionalized nanowires. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:13066-71. [PMID: 24063560 DOI: 10.1021/la402888b] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Two different methods to self-assemble red- or yellow-luminescent nucleic acids-stabilized Ag nanoclusters (NCs) nanowires are presented. By one method, the autonomous hybridization-polymerization process between two nucleic acids leads to polymer chains consisting of sequence-specific loops for the stabilization of the red- or yellow-emitting Ag NCs. By the other method, the nucleic acid-triggered hybridization chain reaction (HCR) involving the cross-opening of two functional hairpins leads to sequence-specific DNA loops and a nucleic acid scaffold that stabilize the respective red- or yellow-emitting Ag NCs. The micrometer-long luminescent Ag NC-functionalized nanowires are imaged by AFM and confocal microscopy.
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Affiliation(s)
- Ron Orbach
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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