InterPro domain: IPR008148

Similar to the distantly related microbial class I photolyases, class 2 enzymes repair UV-induced cyclobutane pyrimidine dimer (CPD) lesions within duplex DNA using blue/near-UV light [ 1 ]. There are a number of conserved sequence regions in all known class 2 DNA photolyases, especially in the C-terminal part. The structures of the class 2 DNA photolyase from archaea and rice have been solved [ 2 , 2 ].

The cryptochrome and photolyase families consist of structurally related flavin adenine dinucleotide (FAD) proteins that use the absorption of blue light to accomplish different tasks. The photolyasess use the blue light for light-driven electron transfer to repair UV-damaged DNA, while the cryptochromes are blue-light photoreceptors involved in the circadian clock for plants and animals [ 3 , 4 ]. On the basis of the primary structure, the cryptochrome/DNA photolyase family can be grouped into two classes [ 5 ]. The first class contains cryptochromes and DNA photolyases from eubacteria, archaea, fungi, animals and plants. The second class contains DNA photolyases from prokaryotes, plants and animals.

1. Crystal structures of an archaeal class II DNA photolyase and its complex with UV-damaged duplex DNA. EMBO J. 30, 4437-49
2. Eukaryotic class II cyclobutane pyrimidine dimer photolyase structure reveals basis for improved ultraviolet tolerance in plants. J. Biol. Chem. 287, 12060-9
3. Binding of Substrate Locks the Electrochemistry of CRY-DASH into DNA Repair. Biochemistry 54, 2802-5
4. Evolutionary History of the Photolyase/Cryptochrome Superfamily in Eukaryotes. PLoS ONE 10, e0135940
5. A new class of DNA photolyases present in various organisms including aplacental mammals. EMBO J. 13, 6143-51