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EC 4.1.99.13 Details
show Brenda entryEC number
4.1.99.13
Accepted name
(6-4)DNA photolyase
Reaction
(6-4) photoproduct (in DNA) = 2 pyrimidine residues (in DNA)
Other name(s)
DNA photolyase,
H64PRH,
NF-10,
phr (6-4),
PL-(6-4),
OtCPF1,
(6-4) PHR,
At64PHR
Systematic name
(6-4) photoproduct pyrimidine-lyase
CAS registry number
37290-70-3
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
created 2009
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1 Oxidoreductases
1.1.1 With NAD+ or NADP+ as acceptor
1.1.3.1 created 1961, deleted 1984 1.1.3.25 created 1986, deleted 2005 1.1.3.26 created 1989, deleted 2002 1.1.3.31 created 1992, deleted 2003 1.1.3.32 created 1999, deleted 2002 1.1.3.33 created 1999, deleted 2002 1.1.3.34 created 1999, deleted 2002 1.1.3.35 created 1999, deleted 2002 1.1.3.36 created 1999, deleted 2002 1.1.99.15 created 1978, deleted 1980 1.1.99.17 created 1982, deleted 2003
