Role of SOS and OxyR systems in the repair of Escherichia coli submitted to hydrogen peroxide under low iron conditions

被引:17
作者
Asad, LMBO
Asad, NR
Silva, AB
deAlmeida, CEB
Leitao, AC
机构
[1] FED UNIV RIO DE JANEIRO, INST BIOFIS CARLOS CHAGAS FILHO, LAB RADIOBIOL MOL, BR-21949900 RIO DE JANEIRO, BRAZIL
[2] UNIV ESTADO RIO DE JANERIO, INST BIOL, DEPT BIOFIS & BIOMETRIA, BR-20551030 RIO DE JANEIRO, BRAZIL
关键词
hydrogen peroxide; Escherichia coli; SOS response; adaptive response;
D O I
10.1016/S0300-9084(97)80030-2
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
There are at least two mechanisms by which H2O2 induces DNA lesions in Escherichia coli: one in the presence of physiological iron levels and the other in low iron conditions. The survival as well as the induction of SOS response in different DNA repair mutant strains of E coli was evaluated after H2O2 treatment under low iron conditions (pretreatment with an iron chelator). Our results indicate that, in normal iron conditions RecA protein has a relevant role in recombination repair events, while in low iron conditions RecA protein is important as a positive regulator of the SOS response. On the other hand, the oxy Delta R mutant is sensitive to the lethal effects of H2O2 only in low iron conditions and this sensitivity cannot be correlated with DNA strand breaks.
引用
收藏
页码:359 / 364
页数:6
相关论文
共 25 条