Photoreactivation is a DNA repair mechanism where an enzyme called photolyase uses light energy to break the bonds of thymine dimers caused by UV radiation. This process restores the original DNA structure without excising nucleotides.
5 Must Know Facts For Your Next Test
Photoreactivation specifically repairs UV-induced thymine dimers in DNA.
The enzyme photolyase is activated by visible light, particularly blue and near-UV light.
This repair mechanism does not remove nucleotides but rather directly reverses the damage.
Photoreactivation is more common in prokaryotes but also occurs in some eukaryotes like yeast and plants.
It does not operate in dark conditions as it relies on light to activate photolyase.