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Krall JB, Nichols PJ, Henen MA, Vicens Q, Vögeli B. Structure and Formation of Z-DNA and Z-RNA. Molecules 2023; 28:843. [PMID: 36677900 PMCID: PMC9867160 DOI: 10.3390/molecules28020843] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/08/2023] [Accepted: 01/12/2023] [Indexed: 01/17/2023] Open
Abstract
Despite structural differences between the right-handed conformations of A-RNA and B-DNA, both nucleic acids adopt very similar, left-handed Z-conformations. In contrast to their structural similarities and sequence preferences, RNA and DNA exhibit differences in their ability to adopt the Z-conformation regarding their hydration shells, the chemical modifications that promote the Z-conformation, and the structure of junctions connecting them to right-handed segments. In this review, we highlight the structural and chemical properties of both Z-DNA and Z-RNA and delve into the potential factors that contribute to both their similarities and differences. While Z-DNA has been extensively studied, there is a gap of knowledge when it comes to Z-RNA. Where such information is lacking, we try and extend the principles of Z-DNA stability and formation to Z-RNA, considering the inherent differences of the nucleic acids.
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Affiliation(s)
- Jeffrey B. Krall
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Parker J. Nichols
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Morkos A. Henen
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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2
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Epstein RJ, Lin FPY, Brink RA, Blackburn J. Synonymous alterations of cancer-associated Trp53 CpG mutational hotspots cause fatal developmental jaw malocclusions but no tumors in knock-in mice. PLoS One 2023; 18:e0284327. [PMID: 37053216 PMCID: PMC10101519 DOI: 10.1371/journal.pone.0284327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Intragenic CpG dinucleotides are tightly conserved in evolution yet are also vulnerable to methylation-dependent mutation, raising the question as to why these functionally critical sites have not been deselected by more stable coding sequences. We previously showed in cell lines that altered exonic CpG methylation can modify promoter start sites, and hence protein isoform expression, for the human TP53 tumor suppressor gene. Here we extend this work to the in vivo setting by testing whether synonymous germline modifications of exonic CpG sites affect murine development, fertility, longevity, or cancer incidence. We substituted the DNA-binding exons 5-8 of Trp53, the mouse ortholog of human TP53, with variant-CpG (either CpG-depleted or -enriched) sequences predicted to encode the normal p53 amino acid sequence; a control construct was also created in which all non-CpG sites were synonymously substituted. Homozygous Trp53-null mice were the only genotype to develop tumors. Mice with variant-CpG Trp53 sequences remained tumor-free, but were uniquely prone to dental anomalies causing jaw malocclusion (p < .0001). Since the latter phenotype also characterises murine Rett syndrome due to dysfunction of the trans-repressive MeCP2 methyl-CpG-binding protein, we hypothesise that CpG sites may exert non-coding phenotypic effects via pre-translational cis-interactions of 5-methylcytosine with methyl-binding proteins which regulate mRNA transcript initiation, expression or splicing, although direct effects on mRNA structure or translation are also possible.
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Affiliation(s)
- Richard J Epstein
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
| | - Frank P Y Lin
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Centre for Clinical Genomics, The Kinghorn Cancer Centre, Sydney, Australia
| | - Robert A Brink
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
| | - James Blackburn
- University of New South Wales, St Vincent's Hospital Campus, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
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3
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Schulze-Adams M, Touboul D, Bernet B, Vasella A. Oligonucleotide Analogues with Integrated Bases and Backbone (ONIB). Part 31. Helv Chim Acta 2014. [DOI: 10.1002/hlca.201400156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Nadler A, Diederichsen U. Guanosine Analog with Respect to Z-DNA Stabilization: Nucleotide with Combined C8-Bromo and C2′-Ethynyl Modifications. European J Org Chem 2008. [DOI: 10.1002/ejoc.200700991] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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Heinrich D, Wagner T, Diederichsen U. Synthesis and DNA Incorporation of an Ethynyl-Bridged Cytosine C-Nucleoside as Guanosine Surrogate. Org Lett 2007; 9:5311-4. [DOI: 10.1021/ol7025334] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel Heinrich
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
| | - Thomas Wagner
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
| | - Ulf Diederichsen
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
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6
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Abstract
Biologists were puzzled by the discovery of left-handed Z-DNA because it seemed unnecessary. Z-DNA was stabilized by the negative supercoiling generated by transcription, which indicated a transient localized conformational change. Few laboratories worked on the biology of Z-DNA. However, the discovery that certain classes of proteins bound to Z-DNA with high affinity and great specificity indicated a biological role. The most recent data show that some of these proteins participate in the pathology of poxviruses.
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Affiliation(s)
- Alexander Rich
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 68-233, Cambridge, Massachusetts 02139, USA
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Chen LS, Sheppard TL. Synthesis and hybridization properties of RNA containing 8-chloroadenosine. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2003; 21:599-617. [PMID: 12484453 DOI: 10.1081/ncn-120015071] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
8-Chloroadenosine (8-Cl-Ado) has shown potential as a chemotherapeutic agent for the treatment of multiple myeloma and certain leukemias. 8-Cl-Ado treatment leads to a decrease in global RNA levels and incorporation of the analog into cellular RNA in malignant cells. To investigate the effects of 8-Cl-Ado modifications on RNA structure and function, an 8-Cl-Ado phosphoramidite and controlled-pore glass support were synthesized and used to introduce 8-Cl-Ado at internal and 3'- terminal positions, respectively. RNA oligonucleotides containing 8-chloroadenine (8-Cl-A) residues were synthesized and hybridized with complementary RNA strands. Circular dichroism spectroscopy of the resulting RNA duplexes revealed that the modified nucleobase does not perturb the overall A-form helix geometry. The thermal stabilities of 8-Cl-Ado modified duplexes were determined by UV thermal denaturation analysis and were compared with analogous natural duplexes containing standard and mismatched base pairs. The 8-Cl-Ado modification destabilizes RNA duplexes by approximately 5 kcal/mole, approximately as much as a U:U mismatched base pair. The duplex destabilization of 8-Cl-A may result from perturbation of Watson-Crick base pairing induced by conformational preferences of 8-halogenated nucleosides.
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Affiliation(s)
- Lisa S Chen
- Department of Chemistry, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
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Chen LS, Bahr MH, Sheppard TL. Effects of 8-chlorodeoxyadenosine on DNA synthesis by the Klenow fragment of DNA polymerase I. Bioorg Med Chem Lett 2003; 13:1509-12. [PMID: 12699743 DOI: 10.1016/s0960-894x(03)00204-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
8-chloro-2'-deoxyadenosine (8-Cl-dAdo) was incorporated into synthetic DNA oligonucleotides to determine its effects on DNA synthesis by the 3'-5' exonuclease-free Klenow fragment of Escherichia coli DNA Polymerase I (KF-). Single nucleotide insertion experiments were used to determine the coding potential of 8-Cl-dAdo in a DNA template. KF- inserted TTP opposite 8-Cl-dAdo in the template, but with decreased efficiency relative to natural deoxyadenosine. Running-start primer extensions with KF- resulted in polymerase pausing at 8-Cl-dAdo template sites during DNA synthesis. The 2'-deoxyribonucleoside triphosphate analogue, 8-Cl-dATP, was incorporated opposite thymidine (T) approximately two-fold less efficiently than dATP.
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Affiliation(s)
- Lisa S Chen
- Department of Chemistry, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
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Taboury JA, Taillandier E, Lumbroso P, Neumann JM, Tran-Dinh S, d'Estaintot BL, Huynh-Dinh T, Igolen J. Z helix-coil transition of d(C-Br8G-C-G-C-Br8G) studied by CD, 1H-NMR and IR spectroscopies. J Biomol Struct Dyn 1985; 2:1185-203. [PMID: 2855786 DOI: 10.1080/07391102.1985.10507632] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The conformation of d(C-Br8G-C-G-C-Br8G) in aqueous solution was studied by CD and 1H-NMR spectroscopy and in condensed phase by IR spectroscopy. Whether in 0.1 M or 3 M NaCl solution or in film the only double helical structure adopted by brominated d(C-G)3 oligomer is the Z form. The IR spectrum of the film presents all the characteristic absorptions of the Z conformation and in particular is indicative of a syn conformation for the central guanosine as well as for the brominated one. Imino proton resonances of d(C-Br8G-C-G-C-Br8G) demonstrating the duplex formation were observed up to 60 degrees C. It is interesting to note that the significant highfield shifts of the dC H5" exocyclic sugar protons characteristic of the non exchangeable proton spectra of d(C-G)3 containing 5-methyl dC residues in the Z form were also detected in the proton spectrum of brominated oligomer. Whereas formation of the Z helix of methylated d(C-G)3 oligomers dependent on the salt concentration was found to occur via the preliminary formation of a B helix even in 4 M NaCl solution, the Z helix of d(C-Br8G-C-G-C-Br8G) is obtained directly from the coil form. However, IR data suggest that in the Z form of d(C-Br8G-C-G-C-Br8G), the overlapping of the base planes should be slightly different in comparison with the stacking observed in d(C-G)3 crystals. The kinetic data (activation energy and lifetime) of the Z helix-coil transition of brominated d(C-G)3 are compared to those of the B helix-coil transition observed for methylated d(C-G)3 in 0.1 M NaCl solution while the thermodynamic data of these two reactions (enthalpy and midpoint temperature) are slightly different.
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Affiliation(s)
- J A Taboury
- Laboratoire de Spectroscopie Biomoléculaire, UER Santé-Médecine Biologie Humaine, Bobigny, France
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Uesugi S, Ohkubo M, Ohtsuka E, Ikehara M, Kobayashi Y, Kyogoku Y. Synthesis and conformational studies of ribooligonucleotides which contain an alternating C-G sequence and show unusual circular dichroism spectra. Nucleic Acids Res 1984; 12:7793-810. [PMID: 6493981 PMCID: PMC320201 DOI: 10.1093/nar/12.20.7793] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The poly [r(C-G)] duplex shows an unusually large negative CD band in the long wavelength region. In order to elucidate this phenomenon, r(C-G-C-G) and r(C-G-C-G-C-G) were synthesized by a phosphotriester method and their properties were examined by UV, CD, 1H and 31P NMR spectroscopy. These ribooligomers form self-duplexes at low temperature, the CD spectra of which show negative bands at around 290 nm and positive bands at around 265 nm. The results of 1H nuclear Overhauser effect experiments, 1H chemical shift-temperature profiles of base protons, and the sharp singlet observed for all H1' protons are consistent with a normal A-RNA structure but not with a Z-DNA like structure. The CD-temperature profiles and 31P NMR spectra support this conclusion. These results indicate that RNA duplexes with an alternating C-G sequence can give an unusually large negative CD band in the long wavelength region despite their right-handed helical structure.
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Westerink HP, van der Marel GA, van Boom JH, Haasnoot CA. Conformational analysis of r(CGCGCG) in aqueous solution: an A-type double helical conformation studied by two-dimensional nuclear Overhauser effect spectroscopy. Nucleic Acids Res 1984; 12:4323-38. [PMID: 6728679 PMCID: PMC318834 DOI: 10.1093/nar/12.10.4323] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The conformation of the hexanucleoside pentaphosphate r( CGCGCG ) in aqueous solution was studied by circular dichroism, 1H- and 31P-NMR spectroscopy. The base-, H1'- and H2'-proton resonances were assigned by means of 2D-NOE spectroscopy. The base- and H1'-proton chemical shifts were studied as a function of temperature. Proton-proton distances are computed in A- and A'-RNA as well as in A-, B- and Z-DNA. A qualitative interpretation of the observed 2D-NOE intensities shows that r( CGCGCG ) adopts a regular A-type double helical conformation under our experimental conditions. The CD- and 31P-NMR experiments described in this paper are in agreement with this structure both under low- and high-salt conditions.
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12
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Uesugi S, Ohkubo M, Ohtsuka E, Ikehara M, Kobayashi Y, Kyogoku Y, Westerink HP, van der Marel GA, van Boom JH, Haasnoot CA. Conformation of ribooligonucleotide duplexes containing an alternating C-G sequence which show an unusual circular dichroism spectrum. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)43416-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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13
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Möller A, Nordheim A, Kozlowski SA, Patel DJ, Rich A. Bromination stabilizes poly(dG-dC) in the Z-DNA form under low-salt conditions. Biochemistry 1984; 23:54-62. [PMID: 6691966 DOI: 10.1021/bi00296a009] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Using circular dichroism studies, Pohl & Jovin (1972) [Pohl, F.M., & Jovin, T.M. (1972) J. Mol. Biol. 67, 375-396] demonstrated that poly(dG-dC) undergoes a salt-dependent conformational change characterized by a spectral inversion. The low-salt form corresponds to the right-handed B form of DNA and the high-salt form to the left-handed Z-DNA helix. Modification of poly(dG-dC) by adding bromine atoms to the C8 position of guanine and the C5 position of cytosine residues stabilized this polymer in the Z-DNA form under low-salt conditions. The guanine residues were found to be twice as reactive as the cytosine residues. With a modification of 38% Br8G and 18% Br5C, the polymers formed a stable Z-DNA helix under physiological conditions. The bromination produced spectroscopic features very similar to poly(dG-dC) in 4 M NaCl. However, bromination did not freeze the Z structure as was shown by ethidium bromide intercalation studies. Addition of the dye favored an intercalated B-DNA form. The conversion of B- to Z-DNA leads to profound conformational changes which were also seen by a reduced insensitivity to various exo- and endonucleases. Comparative studies showed that the brominated polymers have a high affinity to nitrocellulose filters. In 1 M NaCl, there was virtually no binding of B-DNA, but a substantial binding of Z-DNA was found even at rather low levels of bromination.(ABSTRACT TRUNCATED AT 250 WORDS)
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