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Doppleb O, Schwarz RJ, Landa M, Richert C. Efficient Oligomerization of Aromatic Amino Acids Induced by Gaps in Four-Helix Bundles of DNA or RNA. Chemistry 2022; 28:e202104104. [PMID: 35050538 PMCID: PMC9303611 DOI: 10.1002/chem.202104104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 11/09/2022]
Abstract
The formation of peptides from amino acids is one of the processes associated with life. Because of the dominant role of translation in extant biology, peptide‐forming processes that are RNA induced are of particular interest. We have previously reported the formation of phosphoramidate‐linked peptido RNAs as the products of spontaneous condensation reactions between ribonucleotides and free amino acids in aqueous solution. We now asked whether four‐helix bundle (4HB) DNA or RNA folding motifs with a single‐ or double‐nucleotide gap next to a 5’‐phosphate can act as reaction sites for phosphoramidate formation. For glycine, this was found to be the case, whereas phenylalanine and tryptophan showed accelerated formation of peptides without a covalent link to the nucleic acid. Free peptides with up to 11 tryptophan or phenylalanine residues were found in precipitates forming in the presence of gap‐containing DNA or RNA 4HBs. Control experiments using motifs with just a nick or primer alone did not have the same effect. Because folded structures with a gap in a double helix are likely products of hybridization of strands formed in statistically controlled oligomerization reactions, our results are interesting in the context of prebiotic scenarios. Independent of a putative role in evolution, our findings suggest that for some aromatic amino acids an RNA‐induced pathway for oligomerization exists that does not have a discernable link to translation.
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Affiliation(s)
- Olivia Doppleb
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Rainer Joachim Schwarz
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Maria Landa
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Clemens Richert
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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2
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Kamble N, Wolfrum M, Halbritter T, Sigurdsson ST, Richert C. Noncovalent Spin-Labeling of DNA and RNA Triplexes. Chem Biodivers 2019; 17:e1900676. [PMID: 31872549 DOI: 10.1002/cbdv.201900676] [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: 11/27/2019] [Accepted: 12/23/2019] [Indexed: 11/07/2022]
Abstract
Studying nucleic acids often requires labeling. Many labeling approaches require covalent bonds between the nucleic acid and the label, which complicates experimental procedures. Noncovalent labeling avoids the need for highly specific reagents and reaction conditions, and the effort of purifying bioconjugates. Among the least invasive techniques for studying biomacromolecules are NMR and EPR. Here, we report noncovalent labeling of DNA and RNA triplexes with spin labels that are nucleobase derivatives. Spectroscopic signals indicating strong binding were detected in EPR experiments in the cold, and filtration assays showed micromolar dissociation constants for complexes between a guanine-derived label and triplex motifs containing a single-nucleotide gap in the oligopurine strand. The advantages and challenges of noncovalent labeling via this approach that complements techniques relying on covalent links are discussed.
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Affiliation(s)
- Nilesh Kamble
- Science Institute, University of Iceland, Dunhaga 3, 107 R, eykjavik, Iceland
| | - Manpreet Wolfrum
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Thomas Halbritter
- Science Institute, University of Iceland, Dunhaga 3, 107 R, eykjavik, Iceland
| | - Snorri T Sigurdsson
- Science Institute, University of Iceland, Dunhaga 3, 107 R, eykjavik, Iceland
| | - Clemens Richert
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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3
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Feldner T, Wolfrum M, Richert C. Turning DNA Binding Motifs into a Material for Flow Cells. Chemistry 2019; 25:15288-15294. [PMID: 31483908 PMCID: PMC6916365 DOI: 10.1002/chem.201903631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/03/2019] [Indexed: 01/18/2023]
Abstract
Nanoscale assemblies of DNA strands are readily designed and can be generated in a wide range of shapes and sizes. Turning them into solids that bind biomolecules reversibly, so that they can act as active material in flow cells, is a challenge. Among the biomolecular ligands, cofactors are of particular interest because they are often the most expensive reagents of biochemical transformations, for which controlled release and recycling are desirable. We have recently described DNA triplex motifs that bind adenine-containing cofactors, such as NAD, FAD and ATP, reversibly with low micromolar affinity. We sought ways to convert the soluble DNA motifs into a macroporous solid for cofactor binding. While assemblies of linear and branched DNA motifs produced hydrogels with undesirable properties, long DNA triplexes treated with protamine gave materials suitable for flow cells. Using exchangeable cells in a flow system, thermally controlled loading and discharge were demonstrated. Employing a flow cell loaded with ATP, bioluminescence was induced through thermal release of the cofactor. The results show that materials generated from functional DNA structures can be successfully employed in macroscopic devices.
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Affiliation(s)
- Tobias Feldner
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Manpreet Wolfrum
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Clemens Richert
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
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4
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Wolfrum M, Schwarz RJ, Schwarz M, Kramer M, Richert C. Stabilizing DNA nanostructures through reversible disulfide crosslinking. NANOSCALE 2019; 11:14921-14928. [PMID: 31360975 DOI: 10.1039/c9nr05143k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Designed DNA nanostructures can be generated in a wide range of sizes and shapes and have the potential to become exciting tools in material sciences, catalysis and medicine. However, DNA nanostructures are thermally labile assemblies of delicate biomacromolecules, and the lability hampers the use in many applications. Disulfide crosslinking is nature's successful approach to stabilize folded proteins against denaturation. It is therefore interesting to ask whether similar approaches can be used to stabilize DNA nanostructures. Here we report the synthesis of two 2'-deoxynucleoside phosphoramidites and two nucleosides linked to controlled pore glass that can be used to prepare oligodeoxynucleotides with protected thiol groups via automated DNA synthesis. Strands with one, two, three or four thiol-bearing nucleotides were prepared. One nicked duplex and three different nanostructures were assembled, the protected thiols were liberated under non-denaturing conditions, and disulfide crosslinking was induced with oxygen. Up to 19 crosslinks were thus placed in folded DNA structures up to 1456 nucleotides in size. The crosslinked structures had increased thermal stability, with UV-melting points 9-50 °C above that of the control structure. Disulfides were converted back to free thiols under reducing conditions. The redox-dependent increase in stability makes crosslinked DNA nanostructures attractive for the construction of responsive materials and biomedical applications.
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Affiliation(s)
- Manpreet Wolfrum
- Institute of Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany.
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5
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Kanamori T, Masaki Y, Oda Y, Ohzeki H, Ohkubo A, Sekine M, Seio K. DNA triplex-based fluorescence turn-on sensors for adenosine using a fluorescent molecular rotor 5-(3-methylbenzofuran-2-yl) deoxyuridine. Org Biomol Chem 2019; 17:2077-2080. [DOI: 10.1039/c8ob02747a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluorescence turn-on detection of adenosine based on microenvironmental and conformational changes of a fluorescent molecular rotor in the DNA triplex is reported.
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Affiliation(s)
- Takashi Kanamori
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Yoshiaki Masaki
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Yuki Oda
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Hiroki Ohzeki
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Akihiro Ohkubo
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Mitsuo Sekine
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
| | - Kohji Seio
- Department of Life Science
- Tokyo Institute of Technology
- Yokohama 226-8501
- Japan
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6
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Clemens Richert. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Clemens Richert. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/anie.201702480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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Schwarz RJ, Richert C. A four-helix bundle DNA nanostructure with binding pockets for pyrimidine nucleotides. NANOSCALE 2017; 9:7047-7054. [PMID: 28327725 DOI: 10.1039/c7nr00094d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Designed DNA nanostructures of impressive size have been described, but designed structures of the size of protein enzymes that bind organic ligands with high specificity are rare. Here we report a four-helix motif consisting of three synthetic strands with 65 base pairs and 165 nucleotides in total that folds well. Furthermore, we show that in the interior of this small folded DNA nanostructure, cavities can be set up that bind pyrimidine nucleotides with micromolar affinity. Base-specific binding for both thymidine and cytidine derivatives is demonstrated. The binding affinity depends on the position in the structure, as expected for recognition beyond simple base pairing. The folding motif reported here can help to expand DNA nanotechnology into the realm of selective molecular recognition that is currently dominated by protein-based enzymes and receptors.
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Affiliation(s)
- Rainer Joachim Schwarz
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
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Kalinowski M, Haug R, Said H, Piasecka S, Kramer M, Richert C. Phosphoramidate Ligation of Oligonucleotides in Nanoscale Structures. Chembiochem 2016; 17:1150-5. [PMID: 27225865 DOI: 10.1002/cbic.201600061] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Indexed: 01/25/2023]
Abstract
The folding of long DNA strands into designed nanostructures has evolved into an art. Being based on linear chains only, the resulting nanostructures cannot readily be transformed into covalently linked frameworks. Covalently linking strands in the context of folded DNA structures requires a robust method that avoids sterically demanding reagents or enzymes. Here we report chemical ligation of the 3'-amino termini of oligonucleotides and 5'-phosphorylated partner strands in templated reactions that produce phosphoramidate linkages. These reactions produce inter-nucleotide linkages that are isoelectronic and largely isosteric to phosphodiesters. Ligations were performed at three levels of complexity, including the extension of branched DNA hybrids and the ligation of six scaffold strands in a small origami.
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Affiliation(s)
- Matthäus Kalinowski
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Rüdiger Haug
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Hassan Said
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Sylwia Piasecka
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Markus Kramer
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Clemens Richert
- Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
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Vollmer S, Richert C. DNA Triplexes That Bind Several Cofactor Molecules. Chemistry 2015; 21:18613-22. [PMID: 26561335 DOI: 10.1002/chem.201503220] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Indexed: 12/29/2022]
Abstract
Cofactors are critical for energy-consuming processes in the cell. Harnessing such processes for practical applications requires control over the concentration of cofactors. We have recently shown that DNA triplex motifs with a designed binding site can be used to capture and release nucleotides with low micromolar dissociation constants. In order to increase the storage capacity of such triplex motifs, we have explored the limits of ligand binding through designed cavities in the oligopurine tract. Oligonucleotides with up to six non-nucleotide bridges between purines were synthesized and their ability to bind ATP, cAMP or FAD was measured. Triplex motifs with several single-nucleotide binding sites were found to bind purines more tightly than triplexes with one large binding site. The optimized triplex consists of 59 residues and four C3-bridges. It can bind up to four equivalents of ligand with apparent Kd values of 52 µM for ATP, 9 µM for FAD, and 2 µM for cAMP. An immobilized version fuels bioluminescence via release of ATP at body temperature. These results show that motifs for high-density capture, storage and release of energy-rich biomolecules can be constructed from synthetic DNA.
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Affiliation(s)
- Sven Vollmer
- Institut für Organische Chemie, Universität Stuttgart, 70569 Stuttgart (Germany), Fax: (+49) 711-685-64321
| | - Clemens Richert
- Institut für Organische Chemie, Universität Stuttgart, 70569 Stuttgart (Germany), Fax: (+49) 711-685-64321.
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11
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Vollmer S, Richert C. Effect of preorganization on the affinity of synthetic DNA binding motifs for nucleotide ligands. Org Biomol Chem 2015; 13:5734-42. [PMID: 25902412 DOI: 10.1039/c5ob00508f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Triplexes with a gap in the purine strand have been shown to bind adenosine or guanosine derivatives through a combination of Watson-Crick and Hoogsteen base pairing. Rigidifying the binding site should be advantageous for affinity. Here we report that clamps delimiting the binding site have a modest effect on affinity, while bridging the gap of the purine strand can strongly increase affinity for ATP, cAMP, and FAD. The lowest dissociation constants were measured for two-strand triple helical motifs with a propylene bridge or an abasic nucleoside analog, with Kd values as low as 30 nM for cAMP in the latter case. Taken together, our data suggest that improving preorganization through covalent bridges increases the affinity for nucleotide ligands. But, a bulky bridge may also block one of two alternative binding modes for the adenine base. The results may help to design new receptors, switches, or storage motifs for purine-containing ligands.
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Affiliation(s)
- S Vollmer
- Institute for Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany.
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12
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Zhuang Z, Pan R, Zhang Q, Huang H. Molecular recognition of pyrimidine nucleobases by triplex DNA receptors. Bioorg Med Chem Lett 2015; 25:1520-4. [DOI: 10.1016/j.bmcl.2015.02.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 11/29/2022]
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13
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Abstract
Incorporation of a 5-methyl-2-thiocytosine base to the parallel homopyrimidine region of a triplex DNA receptor enabled selective molecular recognition of an inosine ligand.
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Affiliation(s)
- Haidong Huang
- Department of Chemistry and Environmental Science
- New Jersey Institute of Technology
- Newark
- USA
| | - Peter C. Tlatelpa
- Department of Chemistry and Environmental Science
- New Jersey Institute of Technology
- Newark
- USA
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14
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Kröner C, Thunemann M, Vollmer S, Kinzer M, Feil R, Richert C. Endless: a purine-binding RNA motif that can be expressed in cells. Angew Chem Int Ed Engl 2014; 53:9198-202. [PMID: 25045108 DOI: 10.1002/anie.201403579] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/29/2014] [Indexed: 01/16/2023]
Abstract
It is becoming increasingly clear that nature uses RNAs extensively for regulating vital functions of the cell, and short sequences are frequently used to suppress gene expression. However, controlling the concentration of small molecules intracellularly through designed RNA sequences that fold into ligand-binding structures is difficult. The development of "endless", a triplex-based folding motif that can be expressed in mammalian cells and binds the second messenger 3',5'-cyclic guanosine monophosphate (cGMP), is described. In vitro, DNA or RNA versions of endless show low micromolar to nanomolar dissociation constants for cGMP. To test its functionality in vivo, four endless RNA motifs arranged in tandem were co-expressed with a fluorescent cGMP sensor protein in murine vascular smooth muscle cells. Nitric oxide induced endogenous cGMP signals were suppressed in endless-expressing cells compared to cells expressing a control motif, which suggests that endless can act as a genetically encoded cGMP sink to modulate signal transduction in cells.
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Affiliation(s)
- Christoph Kröner
- Institut für Organische Chemie, Universität Stuttgart, 70569 Stuttgart (Germany)
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15
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Kröner C, Thunemann M, Vollmer S, Kinzer M, Feil R, Richert C. Endless: A Purine-Binding RNA Motif that Can Be Expressed in Cells. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403579] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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16
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Curtis EA, Liu DR. A naturally occurring, noncanonical GTP aptamer made of simple tandem repeats. RNA Biol 2014; 11:682-92. [PMID: 24824832 PMCID: PMC4156500 DOI: 10.4161/rna.28798] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recently, we used in vitro selection to identify a new class of naturally occurring GTP aptamer called the G motif. Here we report the discovery and characterization of a second class of naturally occurring GTP aptamer, the “CA motif.” The primary sequence of this aptamer is unusual in that it consists entirely of tandem repeats of CA-rich motifs as short as three nucleotides. Several active variants of the CA motif aptamer lack the ability to form consecutive Watson-Crick base pairs in any register, while others consist of repeats containing only cytidine and adenosine residues, indicating that noncanonical interactions play important roles in its structure. The circular dichroism spectrum of the CA motif aptamer is distinct from that of A-form RNA and other major classes of nucleic acid structures. Bioinformatic searches indicate that the CA motif is absent from most archaeal and bacterial genomes, but occurs in at least 70 percent of approximately 400 eukaryotic genomes examined. These searches also uncovered several phylogenetically conserved examples of the CA motif in rodent (mouse and rat) genomes. Together, these results reveal the existence of a second class of naturally occurring GTP aptamer whose sequence requirements, like that of the G motif, are not consistent with those of a canonical secondary structure. They also indicate a new and unexpected potential biochemical activity of certain naturally occurring tandem repeats.
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Affiliation(s)
- Edward A Curtis
- Department of Chemistry and Chemical Biology and Howard Hughes Medical Institute; Harvard University; Cambridge, MA USA
| | - David R Liu
- Department of Chemistry and Chemical Biology and Howard Hughes Medical Institute; Harvard University; Cambridge, MA USA
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17
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Kröner C, Göckel A, Liu W, Richert C. Binding cofactors with triplex-based DNA motifs. Chemistry 2013; 19:15879-87. [PMID: 24194407 DOI: 10.1002/chem.201303098] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Indexed: 12/28/2022]
Abstract
Cofactors are pivotal compounds for the cell and many biotechnological processes. It is therefore interesting to ask how well cofactors can be bound by oligonucleotides designed not to convert but to store and release these biomolecules. Here we show that triplex-based DNA binding motifs can be used to bind nucleotides and cofactors, including NADH, FAD, SAM, acetyl CoA, and tetrahydrofolate (THF). Dissociation constants between 0.1 μM for SAM and 35 μM for THF were measured. A two-nucleotide gap still binds NADH. The selectivity for one ligand over the others can be changed by changing the sequence of the binding pocket. For example, a mismatch placed in one of the two triplets adjacent to the base-pairing site changes the selectivity, favoring the binding of FAD over that of ATP. Further, changing one of the two thymines of an A-binding motif to cytosine gives significant affinity for G, whereas changing the other does not. Immobilization of DNA motifs gives beads that store NADH. Exploratory experiments show that the beads release the cofactor upon warming to body temperature.
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Affiliation(s)
- Christoph Kröner
- Institut für Organische Chemie, Universität Stuttgart, 70569 Stuttgart (Germany), Fax: (+49) 711-685-64321
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Said H, Schüller VJ, Eber FJ, Wege C, Liedl T, Richert C. M1.3--a small scaffold for DNA origami . NANOSCALE 2013; 5:284-90. [PMID: 23160434 DOI: 10.1039/c2nr32393a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The DNA origami method produces programmable nanoscale objects that form when one long scaffold strand hybridizes to numerous oligonucleotide staple strands. One scaffold strand is dominating the field: M13mp18, a bacteriophage-derived vector 7249 nucleotides in length. The full-length M13 is typically folded by using over 200 staple oligonucleotides. Here we report the convenient preparation of a 704 nt fragment dubbed "M1.3" as a linear or cyclic scaffold and the assembly of small origami structures with just 15-24 staple strands. A typical M1.3 origami is large enough to be visualized by TEM, but small enough to show a cooperativity in its assembly and thermal denaturation that is reminiscent of oligonucleotide duplexes. Due to its medium size, M1.3 origami with globally modified staples is affordable. As a proof of principle, two origami structures with globally 5'-capped staples were prepared and were shown to give higher UV-melting points than the corresponding assembly with unmodified DNA. M1.3 has the size of a gene, not a genome, and may function as a model for gene-based nanostructures. Small origami with M1.3 as a scaffold may serve as a workbench for chemical, physical, and biological experiments.
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Affiliation(s)
- Hassan Said
- Institute for Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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