{PDOC00331}
{PS00394; DNA_PHOTOLYASES_1_1}
{PS00691; DNA_PHOTOLYASES_1_2}
{BEGIN}
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* DNA photolyases class 1 signatures *
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Deoxyribodipyrimidine photolyase (EC 4.1.99.3) (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 first class contains
enzymes from Gram-negative and Gram-positive bacteria, the halophilic
archaebacteria Halobacterium halobium, fungi and plants. Class 1 enzymes bind
either 5,10-MTHF (E.coli, fungi, etc.) or 8-HDF (S.griseus, H.halobium).
This family also includes Arabidopsis cryptochromes 1 (CRY1) and 2 (CRY2),
which are blue light photoreceptors that mediate blue light-induced gene
expression.
There are a number of conserved sequence regions in all known class 1 DNA
photolyases, especially in the C-terminal part. We selected two of these
regions as signature patterns.
-Consensus pattern: T-G-x-P-[LIVM](2)-D-A-x-M-[RA]-x-[LIVM]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Consensus pattern: [DN]-R-x-R-[LIVM]-[LIVMN]-x-[STA]-[STAQ]-F-[LIVMFA]-x-K-x-
L-x(2,3)-W-[KRQ]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Note: See also the entry for class 2 DNA photolyases (see <PDOC00832>).
-Last update: December 2004 / Pattern and text revised.
[ 1] Sancar G.B., Sancar A.
Trends Biochem. Sci. 12:259-261(1987).
[ 2] Jorns M.S.
"DNA photorepair: chromophore composition and function in two classes
of DNA photolyases."
Biofactors 2:207-211(1990).
PubMed=2282137
[ 3] Yasui A., Eker A.P.M., Yasuhira S., Yajima H., Kobayashi T., Takao M.,
Oikawa A.
"A new class of DNA photolyases present in various organisms including
aplacental mammals."
EMBO J. 13:6143-6151(1994).
PubMed=7813451
[ 4] Lin C., Ahmad M., Cashmore A.R.
"Arabidopsis cryptochrome 1 is a soluble protein mediating blue
light-dependent regulation of plant growth and development."
Plant J. 10:893-902(1996).
PubMed=8953250
{END}