Pyrimidine dimers represent molecular lesions originating from thymine or cytosine bases within DNA, resulting from photochemical reactions. [1][2] These lesions, commonly linked to direct DNA damage, [3] are induced by ultraviolet light (UV), particularly UVC, result in the formation of covalent bonds between adjacent nitrogenous bases along th...

The major type of damage induced by UV light is the formation of pyrimidine dimers, in which adjacent pyrimidines on the same strand of DNA are joined by the formation of a cyclobutane ring resulting from saturation of the double bonds between carbons 5 and 6 (see Figure 5.20A).

Thymine dimers occur when DNA is exposed to UV radiation. The most common form, cis-syn cyclobutane pyrimidine dimer (CPD), is a strong block to replicative DNA polymerases.

Pyrimidine Dimerization UV light exposure of DNA can cause adjacent pyrimidines (commonly thymines; less often, cytosines) on a DNA strand to dimerize. Pyrimidine dimers form at a rate of a bit less than 100 per cell per day!

Most of these lesions are removed by the nucleotide excision repair pathway, which is defective in rare genetic skin disorders referred to as xeroderma pigmentosum. A major role in inducing sunlight-dependent skin cancer mutations is assigned to the …

A pyrimidine dimer is an intrastrand DNA cross-link caused by exposure to ultraviolet light, which can block DNA replication and transcription. Various DNA repair mechanisms exist to remove pyrimidine dimers, as defects in their removal can lead to diseases and cancer in humans.

2023年6月20日 · Ultraviolet radiation with a wavelength of 260 nm will form pyrimidine dimers between adjacent pyrimidines in the DNA. The dimers can be one of two types (Figure 7.11). The major product is a cytobutane-containing thymine dimer (between C5 and C6 of adjacent T's).

Pyrimidine 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 a cyclobutane ring.

Pyrimidine dimer is an intrastrand DNA cross-link, induced by exposure to ultraviolet light (sunlight). Two types of dimers are formed, depending on whether DNA is single-stranded or duplex. Pyrimidine dimers block both DNA replication and transcription and have to be removed to return DNA to its functional state.

Exposure of cells to UV light from the sun causes the formation of pyrimidine dimers in DNA that have the potential to lead to mutation and cancer. In humans, pyrimidine dimers are removed from the genome in the form of ~30 nt-long oligomers by concerted dual incisions.