PROSITE documentation PDOC00832
DNA photolyases class 2 signatures


Deoxyribodipyrimidine photolyase (EC (DNA photolyase) [1,2] is a DNA repair enzyme. It binds to UV-damaged DNA containing pyrimidine dimers and, upon absorbing a near-UV photon (300 to 500 nm), breaks the cyclobutane ring joining the two pyrimidines of the dimer. DNA photolyase is an enzyme that requires two choromophore-cofactors for its activity: a reduced FADH2 and either 5,10-methenyltetrahydrofolate (5,10-MTFH) or an oxidized 8-hydroxy-5-deazaflavin (8-HDF) derivative (F420). The folate or deazaflavin chromophore appears to function as an antenna, while the FADH2 chromophore is thought to be responsible for electron transfer. On the basis of sequence similarities [3] DNA photolyases can be grouped into two classes. The second class contains enzymes from Myxococcus xanthus, methanogenic archaebacteria, insects, fish and marsupial mammals. It is not yet known what second cofactor is bound to class 2 enzymes.

There are a number of conserved sequence regions in all known class 2 DNA photolyases, especially in the C-terminal part. We selected two of these regions as signature patterns.


See also the entry for class 1 DNA photolyases (see <PDOC00331>).

Last update:

November 1995 / First entry.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

DNA_PHOTOLYASES_2_1, PS01083; DNA photolyases class 2 signature 1  (PATTERN)

DNA_PHOTOLYASES_2_2, PS01084; DNA photolyases class 2 signature 2  (PATTERN)


1AuthorsSancar G.B. Sancar A.
SourceTrends Biochem. Sci. 12:259-261(1987).

2AuthorsJorns M.S.
TitleDNA photorepair: chromophore composition and function in two classes of DNA photolyases.
SourceBiofactors 2:207-211(1990).
PubMed ID2282137

3AuthorsYasui A. Eker A.P.M. Yasuhira S. Yajima H. Kobayashi T. Takao M. Oikawa A.
TitleA new class of DNA photolyases present in various organisms including aplacental mammals.
SourceEMBO J. 13:6143-6151(1994).
PubMed ID7813451

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