Effect of the 1-(2'-deoxy-beta-D-ribofuranosyl)-3-nitropyrrole residue on the stability of DNA duplexes and triplexes
| Autor: | Olga Amosova, Jay George, Jacques R. Fresco |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Guanine
Base pair Stereochemistry Deoxyribonucleosides Calorimetry Biology Nucleic Acid Denaturation Cytosine Structure-Activity Relationship Residue (chemistry) chemistry.chemical_compound Helix (Snails) Genetics Pyrroles Base Composition Base Sequence Hydrogen bond Adenine DNA Oligodeoxyribonucleotides Biochemistry chemistry Duplex (building) Nucleic acid Nucleic Acid Conformation Thermodynamics Thymine Research Article |
| Zdroj: | Nucleic Acids Research. 25:1930-1934 |
| ISSN: | 1362-4962 |
| DOI: | 10.1093/nar/25.10.1930 |
| Popis: | 3-Nitropyrrole (M) was introduced as a non-discriminating 'universal' base in nucleic acid duplexes by virtue of small size and a presumed tendency to stack but not hydrogen bond with canonical bases. However, the absence of thermally-induced hyperchromic changes by single-stranded deoxyoligomers in which M alternates with A or C residues shows that M does not stack strongly with A or C nearest neighbors. Yet, the insertion of a centrally located M opposite any canonical base in a duplex is sometimes even less destabilizing than that of some mismatches, and the variation in duplex stability is small. In triplexes, on the other hand, an M residue centrally located in the third strand reduces triplex stability drastically even when the X.Y target base pair is A.T or G. C in a homopurine. homopyrimidine segment. But, when the target duplex opposition is M-T and the third strand residue is T, the presence of M in the test triplet has little effect on triplex stability. Therefore, a lack of hydrogen bonding in an otherwise helix-compatible test triplet cannot be responsible for triplex destabilization when M is the third strand residue. Thus, M is non-discriminating and none-too-destabilizing in a duplex, but in a triplex it is extremely destabilizing when in the third strand. |
| Databáze: | OpenAIRE |
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