Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Narumi, Issei; Sato, Katsuya; Kikuchi, Masahiro
JAERI-Conf 2002-005, p.158 - 171, 2002/03
is characterized by its extraordinary resistance to the lethal and mutagenic effects of ionizing and ultraviolet irradiations and many other DNA-damaging agents. By analyzing a DNA repair-deficient mutant strain, we discovered that a novel protein participates in the extreme radiation resistance of 
. The protein (designated PprA for promoting prominent repair) can recognize DNA strand breaks. Further, PprA would protect irradiation-damaged DNA from exonuclease activity and consequent degradation and thereby ensure DNA repair processes could function. Beside DNA-binding ability, PprA can promote the activities of DNA ligase and RecA, suggesting that PprA functions as a DNA repair-promoting protein to potentiate the effectiveness of DNA repair. These properties enable PprA to use the widespread application 
and 
.
Sato, Katsuya; Kikuchi, Masahiro; Narumi, Issei
JAERI-Conf 2002-005, p.172 - 184, 2002/03
a DNA damage response mechanism. However, the damage response is poorly understood in . By investigating the function of deinococcal proteins, we found that, unlike in 
, LexA is not involved in the regulation of RecA in . This, in turn, led us to speculate that has an alternative DNA damage response mechanism with which to control 
expression. Recently, we discovered that a novel protein regulates the expression of gene. The novel regulatory protein (designated as PprI) also control the induction of 
gene following 
irradiation. Thus, possesses unique mechanisms of DNA damage recognition and repair gene induction.
by pulsed-field gel electrophoresisKikuchi, Masahiro; Narumi, Issei; Kobayashi, Yasuhiko
JAERI-Conf 2002-005, P. 185, 2002/03
The most striking feature of the radioresistant bacterium is that it can mend over 100 double-strand breaks of genomic DNA during post-irradiation incubation. This process can be clearly visualized using pulsed-field gel electrophoresis (PFGE). By a combination of protein synthesis inhibition treatment and PFGE analysis, it was possible to estimate an initial period required for induction of DNA repair proteins (induction time) and a total period required for completing DNA repair (repair time). PFGE is a powerful tool to analyze DNA damage and its repair process.
