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By
Mostafa Abo Elsoud
(National Research Center, Egypt)
Supervised by
Marina Lyashko
Svetlana Aksenova
Laboratory of Radiation Biology (LRB), JINR, Russia.
The SOS response in Escherichia coli bacteria is a set
of inducible physiological reactions that help a cell to
survive after the treatment with various DNAdamaging
agents,
such
as
ultraviolet,
ionizing
radiation and some chemicals.
More than 40 genes are induced in response to DNA
damage as part of the SOS regulon in Escherichia coli.
SOS repair may result in SOS mutagenesis due to the
inhibition of the proofreading activity of the epsilon
subunit of DNA Pol III.
Cyclobutane pyrimidine
dimers (CPD)
And
pyrimidine pyrimidone
photoproductUV
(6-4 PP)
Lex A
RecA
Umuc,
SOS UmuD,
gene boxDinI
RecA*
ssDNA+RecA+ATP
RecA*
DinI
LexA
UmuD
.
umuC
umuD
dinI
UmuD’
.
UmuD2
UmuD’2
UmuC
UmuD2C
UmuD’2C
Pol V
UmuDD’C
UmuDD’