engleski

Induction of the aidB gene in Salmonella typhimurium

The Escherichia coli aidB gene is one of several genes induced in response to alkylation damage caused by treatments with agents that methylate DNA. The aidB gene is regulated by two different mechanisms. An ada-dependent pathway is triggered by methylated damage to DNA while an ada-independent pathway is induced in unaerated cultures or under conditions which cause cytoplasmic acidification. In contrast to the response in E. coli, an adaptive response is not detectable in Salmonella typhimurium, in spite of the presence of adaST gene in this bacterium. The aim of this study was to examine the presence of the aidB gene in S. typhimurium as well as conditions of its induction in an ada-independent fashion. By applying the operon fusion of e. coli aid gene, its induction by anoxia, or by reduced pH has been determined in S. typhimurium cells. The impact of SOS response genes on the induction of aidB gene in these two bacteria has been observed. We have not detected induction of aidB gene in nucleotide excision repair deficient strains of S. typhimurium under anaerobiosis and by acidification of growth media. It has been certified for the first time that the aidB DNA fragment from E. coli hybridizes with genomic DNA from S. typhimurium.

adaptive response; aidB gene; Escherichia coli; Salmonella typhimurium;

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