thymine dimer


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thy·mine di·mer

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.

thymine dimer

a pair of adjacent THYMINE residues in a single POLYNUCLEOTIDE CHAIN that have become chemically bonded, usually by the action of ULTRAVIOLET LIGHT. The lesion can inhibit DNA replication unless repaired. However, the processes responsible for repairing the lesion sometimes make errors, in turn creating MUTATIONS. see XERODERMA PIGMENTOSUM.
References in periodicals archive ?
However, thymine dimer repair was markedly reduced in mice lacking the VDR, indicating that these mice have defective DNA repair mechanisms in UV-induced damage.
Compared with placebo, treated individuals with low baseline MED had a 50% reduction in epidermal sunburned (apoptotic) cells and nearly a 60% reduction in DNA damage, as measured by thymine dimer formation.
Clearly, it has the propensity to prevent cellular damage, as measured by sunburned cells and thymine dimers.
This failure ultimately leads to permanent damage to the DNA--a gene mutation known as a thymine dimer.
These are usually of the thymine dimer type, implicating UVB as the cause.
Barton has found that electron transfer can fix a mutation known as a thymine dimer, in which two thymines on the same DNA strand bond together.
Upon irradiation with ultraviolet (UV) light, two adjacent structures--thymines--along a strand of DNA may fuse into a thymine dimer.
Specifically, UV-C light causes damage to the nucleic acid of microorganisms by the formation of lethal thymine dimers on the microbial DNA.
Tina Alster says "Remergent DNA Repair helps restore thymine dimers, which are pieces of DNA broken by UV exposure.
According to company executives, efficacy tests have demonstrated DN-AGE LS 9653's ability to protect both nuclear and mitochondrial DNA, reducing the formation of thymine dimers caused by UVB absorption and stimulating the natural DNA repair process in skin cells.
Prevent the formation of thymine dimers -- DNA mutations that can lead to skin cancer.