Thymine thymine dimer
WebbThymine dimers are a major mutagenic photoproduct induced by UV radiation. While they have been the subject of extensive theoretical and experimental investigations, … WebbThymine dimers and (6-4)photoproducts were fluence-dependently induced by every UV below 220 nm extending to 150 nm under dry condition. We detected the efficient formation of both types of damage in the shorter UV region, as well as at 260 nm, which had been believed to be the most efficient wavelength for the formation of UV lesions.
Thymine thymine dimer
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WebbThe most easily formed dimer pair in DNA is the thymine–thymine (TT) dimer (uracil in RNA), but cytosine–thymine (CT or TC) and cytosine–cytosine (CC) also occur. 20 The … Webb10 jan. 2024 · Structurally, it is a consequence of characteristic methyl puckered geometries near the conical intersection region. For the thymine dimer in B-DNA, we found new photochemical pathways through conical intersections that could explain the formation of cyclobutadiene dimers and 6-4 photoproducts.
WebbTemplates containing site-specific cis-syn and trans-syn-I thymine dimers were prepared via a combination of solid phase synthesis with photoproduct building blocks and DNA ligation. Extension of a 15-mer primer on the UV dimer-containing templates by Pol delta produced termination and bypass products in a dNTP and PCNA dependent manner. WebbThe most common type of linkage, a thymine dimer, consists of two thymine bases that react with each other and become chemically linked ^8 8. In nucleotide excision repair, the damaged nucleotide (s) are removed along with a surrounding patch of DNA.
WebbThe number of cells per square millimeter positive for thymine dimer formation was determined using immunohistochemical and image analyses. Results: There was no significant difference in thymine dimer formation between nonirradiated and irradiated skin when application of sunscreen preceded each irradiation. WebbThis widespread form of DNA repair is known as nucleotide-excision repair, because the damaged bases (e.g., a thymine dimer) are removed as part of an oligonucleotide containing the lesion (Figure 5.24). Figure 5.24. …
Webb21 apr. 2000 · The cis-syn cyclobutane thymine dimer was found to be the major photoproduct within cellular DNA, whereas the related (6-4) adduct was produced in an approximately 8-fold lower yield. Interestingly, the corresponding Dewar valence isomer could not be detected upon exposure of human cells to biologically relevant doses of …
Webb2 feb. 2007 · Thymine-dimer yields are not the same at all TT doublets in a given DNA sequence, but these yields depend, in poorly understood ways, on the identity of the flanking bases and on local conformation . By exposing DNA to UV light and then measuring the relative photoproduct yields with single-nucleotide resolution, it has been … college of magical knowledge puzzlePyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions, commonly associated with direct DNA damage. Ultraviolet light (UV; particularly UVB) induces the formation of covalent linkages between consecutive bases along the nucleotide chain in the … Visa mer A cyclobutane pyrimidine dimer (CPD) contains a four membered ring arising from the coupling of the two double-bonded carbons of each of the pyrimidines. Such dimers interfere with base pairing during Visa mer Due to the excellent photochemical properties of DNA, this nature-made molecule is damaged by only a tiny fraction of the absorbed photons. DNA transforms more … Visa mer Pyrimidine dimers introduce local conformational changes in the DNA structure, which allow recognition of the lesion by repair enzymes. In most organisms (excluding Visa mer Direct DNA damage is reduced by sunscreen. This prevents sunburn. When the sunscreen is at the surface of the skin, it filters the UV rays, … Visa mer Translesion polymerases frequently introduce mutations at pyrimidine dimers, both in prokaryotes (SOS mutagenesis) and in eukaryotes. … Visa mer A study by Hanson suggests sunscreen that penetrates into the skin and thereby amplifies the amount of free radicals and oxidative stress contributes to the formation of … Visa mer • DNA repair Visa mer college of maasin logocollege of management and design aspiraWebbthymine dimer: a product of ultraviolet irradiation of thymine (free in ice or bound in nucleic acids) in which two thymine residues become linked by formation of a cyclobutane ring involving both C-5's and both C-6's at the expense of the two double bonds; several stereoisomeric forms are possible. college of magical knowledgeWebbDimers found in DNA chains damaged by ULTRAVIOLET RAYS. They consist of two adjacent PYRIMIDINE NUCLEOTIDES, usually THYMINE nucleotides, in which the … college of maasin moodleWebbPyrimidine dimer (PD) is, perhaps, the best-known DNA lesion affecting a single DNA strand. It is an intrastrand cross-link, in which two adjacent pyrimidines are connected by … dr pritham bozeman montanaWebbMost frequently, such dimers form between two thymines (Figure 1) – hence, an alternative name ‘thymine dimer’, but dimers between a thymine and a cytosine, or between two cytosines, can also form (in 50% GC-rich DNA, the ratio … college of management mahidol university cmmu