scholarly journals Engineering DNA nanotubes for resilience in an E. coli TXTL system

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Melissa A Klocke ◽  
Jonathan Garamella ◽  
Hari K K Subramanian ◽  
Vincent Noireaux ◽  
Elisa Franco

Abstract Deoxyribonucleic acid (DNA) nanotechnology is a growing field with potential intracellular applications. In this work, we use an Escherichia coli cell-free transcription–translation (TXTL) system to assay the robustness of DNA nanotubes in a cytoplasmic environment. TXTL recapitulates physiological conditions as well as strong linear DNA degradation through the RecBCD complex, the major exonuclease in E. coli. We demonstrate that chemical modifications of the tiles making up DNA nanotubes extend their viability in TXTL for more than 24 h, with phosphorothioation of the sticky end backbone being the most effective. Furthermore, we show that a Chi-site double-stranded DNA, an inhibitor of the RecBCD complex, extends DNA nanotube lifetime significantly. These complementary approaches are a first step toward a systematic prototyping of DNA nanostructures in active cell-free cytoplasmic environments and expand the scope of TXTL utilization for bioengineering.

2019 ◽  
Author(s):  
Arun Richard Chandrasekaran ◽  
Javier Vilcapoma ◽  
Paromita Dey ◽  
SiuWah Wong-Deyrup ◽  
Bijan K. Dey ◽  
...  

AbstractInherent nanometer-sized features and molecular recognition properties make DNA a useful material in constructing nanoscale objects, with alluring applications in biosensing and drug delivery. However, DNA can be easily degraded by nucleases present in biological fluids, posing a considerable roadblock to realizing the full potential of DNA nanotechnology for biomedical applications. Here we investigated the nuclease resistance and biostability of the multi-stranded motif called paranemic crossover (PX) DNA and discovered a remarkable and previously unreported resistance to nucleases. We show that PX DNA has more than an order of magnitude increased resistance to degradation by DNase I, serum, and urine compared to double stranded DNA. We further demonstrate that the degradation resistance decreases monotonically as DNA crossovers are removed from the structure, suggesting that frequent DNA crossovers disrupt either the binding or catalysis of nucleases or both. Further, we show using mouse and human cell lines that PX DNA does not affect cell proliferation or interfere with biological processes such as myogenesis. These results have important implications for building DNA nanostructures with enhanced biostability, either by adopting PX-based architectures or by carefully engineering crossovers. We contend that such crossover-dependent nuclease resistance could potentially be used to add “tunable biostability” to the many features of DNA nanotechnology.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1332
Author(s):  
Armando Hernandez-Garcia

Proteins and DNA exhibit key physical chemical properties that make them advantageous for building nanostructures with outstanding features. Both DNA and protein nanotechnology have growth notably and proved to be fertile disciplines. The combination of both types of nanotechnologies is helpful to overcome the individual weaknesses and limitations of each one, paving the way for the continuing diversification of structural nanotechnologies. Recent studies have implemented a synergistic combination of both biomolecules to assemble unique and sophisticate protein–DNA nanostructures. These hybrid nanostructures are highly programmable and display remarkable features that create new opportunities to build on the nanoscale. This review focuses on the strategies deployed to create hybrid protein–DNA nanostructures. Here, we discuss strategies such as polymerization, spatial directing and organizing, coating, and rigidizing or folding DNA into particular shapes or moving parts. The enrichment of structural DNA nanotechnology by incorporating protein nanotechnology has been clearly demonstrated and still shows a large potential to create useful and advanced materials with cell-like properties or dynamic systems. It can be expected that structural protein–DNA nanotechnology will open new avenues in the fabrication of nanoassemblies with unique functional applications and enrich the toolbox of bionanotechnology.


Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1255-1271 ◽  
Author(s):  
Anabel Miranda ◽  
Andrei Kuzminov

Abstract RecBCD is a DNA helicase/exonuclease implicated in degradation of foreign linear DNA and in RecA-dependent recombinational repair of chromosomal lesions in E. coli. The low viability of recA recBC mutants vs. recA mutants indicates the existence of RecA-independent roles for RecBCD. To distinguish among possible RecA-independent roles of the RecBCD enzyme in replication, repair, and DNA degradation, we introduced wild-type and mutant combinations of the recBCD chromosomal region on a low-copy-number plasmid into a ΔrecA ΔrecBCD mutant and determined the viability of resulting strains. Our results argue against ideas that RecBCD is a structural element in the replication factory or is involved in RecA-independent repair of chromosomal lesions. We found that RecBCD-catalyzed DNA degradation is the only activity important for the recA-independent viability, suggesting that degradation of linear tails of σ-replicating chromosomes could be one of the RecBCD’s roles. However, since the weaker DNA degradation capacity due a combination of the RecBC helicase and ssDNA-specific exonucleases restores viability of the ΔrecA ΔrecBCD mutant to a significant extent, we favor suppression of chromosomal lesions via linear DNA degradation at reversed replication forks as the major RecA-independent role of the RecBCD enzyme.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1413
Author(s):  
Sofia Ojasalo ◽  
Petteri Piskunen ◽  
Boxuan Shen ◽  
Mauri A. Kostiainen ◽  
Veikko Linko

Viruses are among the most intriguing nanostructures found in nature. Their atomically precise shapes and unique biological properties, especially in protecting and transferring genetic information, have enabled a plethora of biomedical applications. On the other hand, structural DNA nanotechnology has recently emerged as a highly useful tool to create programmable nanoscale structures. They can be extended to user defined devices to exhibit a wide range of static, as well as dynamic functions. In this review, we feature the recent development of virus-DNA hybrid materials. Such structures exhibit the best features of both worlds by combining the biological properties of viruses with the highly controlled assembly properties of DNA. We present how the DNA shapes can act as “structured” genomic material and direct the formation of virus capsid proteins or be encapsulated inside symmetrical capsids. Tobacco mosaic virus-DNA hybrids are discussed as the examples of dynamic systems and directed formation of conjugates. Finally, we highlight virus-mimicking approaches based on lipid- and protein-coated DNA structures that may elicit enhanced stability, immunocompatibility and delivery properties. This development also paves the way for DNA-based vaccines as the programmable nano-objects can be used for controlling immune cell activation.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1502
Author(s):  
Johannes M. Parikka ◽  
Karolina Sokołowska ◽  
Nemanja Markešević ◽  
J. Jussi Toppari

The predictable nature of deoxyribonucleic acid (DNA) interactions enables assembly of DNA into almost any arbitrary shape with programmable features of nanometer precision. The recent progress of DNA nanotechnology has allowed production of an even wider gamut of possible shapes with high-yield and error-free assembly processes. Most of these structures are, however, limited in size to a nanometer scale. To overcome this limitation, a plethora of studies has been carried out to form larger structures using DNA assemblies as building blocks or tiles. Therefore, DNA tiles have become one of the most widely used building blocks for engineering large, intricate structures with nanometer precision. To create even larger assemblies with highly organized patterns, scientists have developed a variety of structural design principles and assembly methods. This review first summarizes currently available DNA tile toolboxes and the basic principles of lattice formation and hierarchical self-assembly using DNA tiles. Special emphasis is given to the forces involved in the assembly process in liquid-liquid and at solid-liquid interfaces, and how to master them to reach the optimum balance between the involved interactions for successful self-assembly. In addition, we focus on the recent approaches that have shown great potential for the controlled immobilization and positioning of DNA nanostructures on different surfaces. The ability to position DNA objects in a controllable manner on technologically relevant surfaces is one step forward towards the integration of DNA-based materials into nanoelectronic and sensor devices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Feng Li ◽  
Wenting Yu ◽  
Jiaojiao Zhang ◽  
Yuhang Dong ◽  
Xiaohui Ding ◽  
...  

AbstractDNA nanostructures have been demonstrated as promising carriers for gene delivery. In the carrier design, spatiotemporally programmable assembly of DNA under nanoconfinement is important but has proven highly challenging due to the complexity–scalability–error of DNA. Herein, a DNA nanotechnology-based strategy via the cascade hybridization chain reaction (HCR) of DNA hairpins in polymeric nanoframework has been developed to achieve spatiotemporally programmable assembly of DNA under nanoconfinement for precise siRNA delivery. The nanoframework is prepared via precipitation polymerization with Acrydite-DNA as cross-linker. The potential energy stored in the loops of DNA hairpins can overcome the steric effect in the nanoframework, which can help initiate cascade HCR of DNA hairpins and achieve efficient siRNA loading. The designer tethering sequence between DNA and RNA guarantees a triphosadenine triggered siRNA release specifically in cellular cytoplasm. Nanoframework provides stability and ease of functionalization, which helps address the complexity–scalability–error of DNA. It is exemplified that the phenylboronate installation on nanoframework enhanced cellular uptake and smoothed the lysosomal escape. Cellular results show that the siRNA loaded nanoframework down-regulated the levels of relevant mRNA and protein. In vivo experiments show significant therapeutic efficacy of using siPLK1 loaded nanoframework to suppress tumor growth.


2019 ◽  
Author(s):  
Jie Deng ◽  
Andreas Walther

We introduce pathway complexity on a multicomponent systems level in chemically fueled transient DNA polymerization system. The systems are based on a monomeric species pool that is fueled by ATP and orchestrated by an enzymatic reaction network (ERN) of ATP-powered ligation and concurrent cleavage. Such systems display autonomous evolution over multiple structural dynamic steady states from monomers to dimers, oligomer of dimers to ultimately randomized polymer structure before being ultimately degraded back to monomers once the fuel is consumed. The enabling key principle is to design monomer species having kinetically selected molecular recognition with respect to the structure-forming step (ATP-powered ligation) by encoding different sticky-end overhangs into the ligation area. However, all formed structures are equally degraded, and the orthogonal molecular recognition of the different starting species are harmonized during the constantly occurring restriction process, leading in consequence to a reconfiguration of the driven dynamic nanostructures on a higher hierarchical level. This non-equilibrium systems chemistry approach to pathway complexity provides new conceptual insights in fuel-driven automatons and autonomous materials design.


2018 ◽  
Vol 4 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Xiwei Wang ◽  
Wei Lai ◽  
Tiantian Man ◽  
Xiangmeng Qu ◽  
Li Li ◽  
...  

Abstract Biosensor design is important to bioanalysis yet challenged by the restricted target accessibility at the biomolecule-surface (bio-surface). The last two decades have witnessed the appearance of various “art-like” DNA nanostructures in one, two, or three dimensions, and DNA nanostructures have attracted tremendous attention for applications in diagnosis and therapy due to their unique properties (e.g., mechanical flexibility, programmable control over their shape and size, easy and high-yield preparation, precise spatial addressability and biocompatibility). DNA nanotechnology is capable of providing an effective approach to control the surface functionality, thereby increasing the molecular recognition ability at the biosurface. Herein, we present a critical review of recent progress in the development of DNA nanostructures in one, two and three dimensions and highlight their biological applications including diagnostics and therapeutics. We hope that this review provides a guideline for bio-surface engineering with DNA nanostructures.


1981 ◽  
Vol 1 (2) ◽  
pp. 136-143
Author(s):  
M Pellegrini ◽  
W E Timberlake ◽  
R B Goldberg

Electron microscopic analysis of reassociated deoxyribonucleic acid (DNA) from the aquatic fungus Achlya bisexualis revealed details of the sequence arrangement of the inverted repeats and both the highly and moderately repetitive sequence clusters. We used the gene 32 protein-ethidium bromide technique for visualizing the DNA molecules, a procedure which provides excellent contrast between single- and double-stranded DNA regions. Long (greater than 6-kilobase) DNA fragments were isolated after reannealing to two different repetitive C0t values, and the renatured structures were then visualized in an electron microscope. Our results showed that the inverted repeat sequences were short (0.5 kilobase, number-average) and separated by nonhomologous DNA of various lengths. These pairs of sequences were not clustered within the genome. Both highly repetitive and moderately repetitive DNA sequences were organized as tandem arrays of precisely paired, regularly repeating units. No permuted clusters of repeating sequences were observed, nor was there evidence of interspersion of repetitive with single-copy DNA sequences in the Achlya genome.


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