Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Dithionite | reduction of the FAD cofactor with dithionite increases the quantum yield of repair | Drosophila melanogaster |
Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli as a MBP-PL-(6-4) fusion protein | Drosophila melanogaster |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Drosophila melanogaster | - |
- |
- |
Purification (Comment) | Organism |
---|---|
fusion protein is purified through a 20-ml amylose column and through heparin-agarose column | Drosophila melanogaster |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
(6-4) photoproduct (in DNA) = 2 pyrimidine residues (in DNA) | The overall repair reaction consists of two distinct steps, one of which is light-independent and the other one light-dependent. In the initial light-independent step, a 6-iminium ion is thought to be generated via proton transfer induced by two histidines highly conserved among the (6-4) photolyases.This intermediate spontaneously rearranges to form an oxetane intermediate by intramolecular nucleophilic attack. In the subsequent light-driven reaction, one electron is believed to be transferred from the fully reduced FAD cofactor (FADH-) to the oxetane intermediate thus forming a neutral FADH radical and an anionic oxetane radical, which spontaneously fractures. The excess electron is then back-transferred to the flavin radical restoring the fully reduced flavin cofactor and a pair of pyrimidine bases | Drosophila melanogaster |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | binding and catalytic properties of the enzyme are investigated using natural substrates, T[6-4]T and T[6-4]C, and the Dewar isomer of (6-4) photoproduct and substrate analogs s5T[6-4]T/thietane, mes5T[6-4]T, and the N-methyl-3T thietane analog of the oxetane intermediate. The enzyme binds to the natural substrates and to mes5T[6-4]T with high affinity and produces a DNase I footprint of about 20 base pairs around the photolesion. Of the four substrates that bind with high affinity to the enzyme, T[6-4]T and T[6-4]C are repaired with relatively high quantum yields compared with the Dewar isomer and the mes5T[6-4]T which are repaired with 300-400-fold lower quantum yield | Drosophila melanogaster | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
(6-4) photolyase | - |
Drosophila melanogaster |
PL-(6-4) | - |
Drosophila melanogaster |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | - |
Drosophila melanogaster |