EC Number   |
General Information |
Reference |
|---|
   4.1.99.13 | evolution |
(6-4)photolyases are broadly distributed in prokaryotes. the PhrB-like photolyases branched at the base of the evolution of the cryptochrome/photolyase family. The prokaryotic (6-4) photolyases are the ancestors of the cryptochrome/photolyase family |
-, 728696 |
| 4.1.99.13 | evolution |
cryptochromes and photolyases are flavoproteins that undergo cascades of electron/hole transfers after excitation of the flavin cofactor. Animal (6-4) photolyases, as well as animal cryptochromes, feature a chain of four tryptophan residues, while other members of the family contain merely a tryptophan triad |
748034 |
| 4.1.99.13 | evolution |
photolyases are efficient DNA repair enzymes that specifically repair either cyclobutane pyrimidine dimers or (6-4) photoproducts in a light-dependent cleavage reaction. The closely related classical cryptochrome blue light photoreceptors do not repair DNA lesions, instead they are involved in regulatory processes. CryB of Rhodobacter sphaeroides has been described as a cryptochrome that affects light-dependent and singlet oxygen-dependent gene expression and is unusual in terms of its cofactor composition. Evidence for a repair activity of (6-4) photoproducts by CryB is described suggesting a dual character combining the functions of cryptochromes and photolyases |
-, 747746 |
| 4.1.99.13 | evolution |
PhrB from Agrobacterium fabrum represents a distinct group of prokaryotic (6-4) photolyases which contain an iron-sulfur cluster and a DMRL chromophore. The family of photolyases and cryptochromes may be divided into seven major phylogenetic groups: CPD photolyases class I, II and III, Cry-DASH proteins, eukaryotic (6-4) photolyases and animal cryptochromes, plant cryptochromes and prokaryotic FeS-BCP (Fe-S bacterial cryptochromes and photolyases) proteins. The terms CPD- and (6-4) photolyases refer to the kind of lesions that are repaired by these proteins, which are cyclopyrimidine dimers and (6-4) photoproducts, respectively. Both kinds of repair are triggered by a rapid electron transfer from the excited flavin adenine dinucleotide (FAD) chromophore to the DNA lesion. A second light reaction, termed photoreduction, results in the transition of oxidized or semi-reduced FAD to fully reduced FAD in photolyases or from oxidized to semi reduced FAD in plant cryptochromes. During photoreduction, electrons are transmitted from the surface via Trp or Tyr residues of the protein to the FAD chromophore. The classical photoreduction pathways in which electrons travel via three conserved Trp residues is realized in most photolyases and in cryptochromes. The group of FeS-BCP proteins is most distantly related to the other members of the cryptochrome/photolyase family. Two members of this group are CryB from Rhodobacter sphaeroides and PhrB from Agrobacterium fabrum. Among FeS-BCP members, amino acid residues in the active center are highly conserved. Loss of the cluster during the early evolution of the other photolyases |
749067 |
| 4.1.99.13 | evolution |
the bacterial (6-4) photolyase PhrB belongs to a phylogenetically ancient group. Photoreduction of PhrB differs from the typical pattern because the amino acid of the electron cascade next to FAD is a tyrosine (Tyr391), whereas photolyases and cryptochromes of other groups have a tryptophan as direct electron donor of FAD. Evolution of the first site of the redox chain has just been possible by tuning the protein structure and environment to manage a downhill hole transfer process from FAD to solvent |
-, 747528 |
| 4.1.99.13 | evolution |
the energy transfer from cofactor 6,7-dimethyl-8-ribityllumazine (DMRL) to FAD might represent a phylogenetically ancient process |
-, 748848 |
| 4.1.99.13 | evolution |
the enzyme belongs to the photolyase/cryptochrome family, a large family of flavoproteins that possess different functions and use blue light as an energy source, phylogenetic analysis. Of the seven members of this gene family, three (CmPHR2, CmPHR5 and CmPHR6) fall within the clade of cryptochrome DASH, three (CmPHR3, CmPHR4 and CmPHR7) group with plant cryptochromes, and one (CmPHR1) is a homologue of (6-4) photolyase. Photolyases repair UV-induced DNA damage, whereas cryptochromes regulate the growth and development of plants in a blue-light dependent manner |
-, 728529 |
| 4.1.99.13 | evolution |
the Trichoderma reesei Cry1 protein is a member of the cryptochrome/photolyase family with 6-4 photoproduct repair activity. The two major types of DNA damage are cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PP), which are repaired under illumination by CPD and 6-4 photolyases, respectively. Phylogenetic analysis and tree, overview |
-, 749130 |
| 4.1.99.13 | malfunction |
both enzyme mutants H354A and H358A of Xenopus (6-4) PHR maintain their repair activity, although the efficiency is much lower than that of the wild-type. Two histidines must work in a concerted manner in the active center of the wild-type enzyme, which significantly raises the repair efficiency |
747287 |
| 4.1.99.13 | malfunction |
conidia of cry1 mutants show decreased photorepair capacity of DNA damage caused by UV light. In contrast, strains overexpressing Cry1 show increased repair, as compared to the parental strain even in the dark |
-, 749130 |
