DNA (6-4) photolyase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: pyrimidine-pyrimidone (6-4) photoproduct (in DNA) = 2 pyrimidine residues (in DNA). Catalyzes the reactivation of ultraviolet-irradiated DNA. [GOC:mah, PMID:11124949]

DNA (6-4) photolyase activity is a critical enzymatic process involved in the repair of DNA damage induced by ultraviolet (UV) radiation. Specifically, it targets and repairs (6-4) photoproducts, which are highly mutagenic lesions formed when two adjacent thymine bases in DNA absorb UV light and become covalently linked. This repair mechanism is crucial for maintaining the integrity of the genome and protecting cells from the detrimental effects of UV radiation. The (6-4) photolyase enzyme binds to the damaged DNA site and utilizes light energy, typically in the visible or near-UV range, to break the covalent bond between the two thymine bases, restoring the original DNA sequence. The mechanism of action involves the formation of a transient covalent bond between the enzyme and the (6-4) photoproduct, followed by the transfer of an electron from the enzyme to the photoproduct, leading to bond cleavage. This process is highly specific and efficient, ensuring accurate DNA repair and minimizing the accumulation of mutations. The (6-4) photolyase enzyme is found in a wide range of organisms, including bacteria, fungi, plants, and animals, highlighting its fundamental role in DNA repair and maintaining genetic stability.'
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Proteins (2)

Compounds (1)