deoxyribodipyrimidine photo-lyase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: cyclobutadipyrimidine (in DNA) = 2 pyrimidine residues (in DNA). This reaction represents the reactivation of irradiated DNA by light. [EC:4.1.99.3]

Deoxyribodipyrimidine photolyase activity is a critical DNA repair mechanism that specifically targets and repairs cyclobutane pyrimidine dimers (CPDs), a common form of DNA damage caused by ultraviolet (UV) radiation. These dimers are formed when adjacent pyrimidine bases (thymine or cytosine) in DNA become covalently linked, distorting the DNA helix and inhibiting DNA replication and transcription. Photolyases utilize a complex enzymatic process powered by light energy to break the covalent bond between the dimerized pyrimidine bases, restoring the original, undamaged DNA sequence.

The process begins with the absorption of light by a chromophore within the photolyase enzyme. This chromophore, typically a flavin adenine dinucleotide (FAD) molecule, becomes photoexcited, transferring energy to the CPD. This energy transfer excites the dimer, weakening the covalent bond between the pyrimidine bases. The photolyase enzyme then facilitates the breaking of the dimer bond, allowing the pyrimidine bases to return to their original, unlinked states.

The repair mechanism of photolyases is highly specific for CPDs, demonstrating an exceptional ability to discriminate between CPDs and other types of DNA damage. This selectivity is crucial for maintaining the integrity of the genome and preventing mutations that can lead to cancer and other diseases.

Overall, deoxyribodipyrimidine photolyase activity is a vital process in maintaining the integrity of DNA by repairing UV-induced damage. This enzymatic process is crucial for the survival of organisms exposed to UV radiation and plays a critical role in preventing the accumulation of mutations that can have deleterious consequences.'
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Proteins (2)

Compounds (1)