KEGG   ENZYME: 4.1.99.13Help
Entry
EC 4.1.99.13                Enzyme                                 

Name
(6-4)DNA photolyase;
DNA photolyase;
H64PRH;
NF-10;
phr (6-4);
PL-(6-4);
OtCPF1;
(6-4) PHR;
At64PHR
Class
Lyases;
Carbon-carbon lyases;
Other carbon-carbon lyases
BRITE hierarchy
Sysname
(6-4) photoproduct pyrimidine-lyase
Reaction(IUBMB)
(6-4) photoproduct (in DNA) = 2 pyrimidine residues (in DNA)
Substrate
(6-4) photoproduct (in DNA)
Product
pyrimidine residues (in DNA)
Comment
A flavoprotein (FAD). 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 [2].
History
EC 4.1.99.13 created 2009
Reference
1  [PMID:19359474]
  Authors
Hitomi K, DiTacchio L, Arvai AS, Yamamoto J, Kim ST, Todo T, Tainer JA, Iwai S, Panda S, Getzoff ED
  Title
Functional motifs in the (6-4) photolyase crystal structure make a comparative framework for DNA repair photolyases and clock cryptochromes.
  Journal
Proc. Natl. Acad. Sci. U. S. A. 106 (2009) 6962-7.
  Sequence
[ath:AT3G15620]
Reference
2  [PMID:17164245]
  Authors
Schleicher E, Hitomi K, Kay CW, Getzoff ED, Todo T, Weber S
  Title
Electron nuclear double resonance differentiates complementary roles for active site histidines in (6-4) photolyase.
  Journal
J. Biol. Chem. 282 (2007) 4738-47.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
37290-70-3

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