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The SOS response of bacteria is a global regulatory network targeted at addressing DNA damage. Governed by the products of the lexA and recA genes, it co-ordinates a comprehensive response against DNA lesions and its description in Escherichia coli has stood for years as a textbook paradigm of stress-response systems in bacteria. In this paper we review the(More)
Previous studies have established that the expression of Salmonella enterica pathogenicity island 1 (SPI1), which is essential for epithelial invasion, is mainly regulated by the HilD protein. The ferric uptake regulator, Fur, in turn modulates the expression of the S. enterica hilD gene, albeit through an unknown mechanism. Here we report that S. enterica(More)
In recent years, the recognition sequence of the SOS repressor LexA protein has been identified for several bacterial clades, such as the Gram-positive, green non-sulfur bacteria and Cyanobacteria phyla, or the 'Alphaproteobacteria', 'Deltaproteobacteria' and 'Gammaproteobacteria' classes. Nevertheless, the evolutionary relationship among these sequences(More)
Integrons are found in the genome of hundreds of environmental bacteria but are mainly known for their role in the capture and spread of antibiotic resistance determinants among Gram-negative pathogens. We report a direct link between this system and the ubiquitous SOS response. We found that LexA controlled expression of most integron integrases and(More)
MOTIVATION Motif-prediction algorithm capabilities for the analysis of bacterial regulatory networks and the prediction of new regulatory sites can be greatly enhanced by the use of comparative genomics approaches. In this study, we make use of a consensus-building algorithm and comparative genomics to conduct an in-depth analysis of the LexA-regulon of(More)
Escherichia coli LexA protein is the repressor of a gene network whose members are directly involved in the repair of damaged DNA and in the survival of bacterial cells until DNA lesions have been eliminated. The lexA gene is widely present in bacteria, although the sequences of only three LexA-binding sites are known: Gram-positive, alpha Proteobacteria(More)
Recently, a multiple gene cassette with mutagenic translation synthesis activity was identified and shown to be under LexA regulation in several proteobacteria species. In this work, we have traced down instances of this multiple gene cassette across the bacteria domain. Phylogenetic analyses show that this cassette has undergone several reorganizations(More)
In contrast to the vast majority of the members of the domain Bacteria, several Pseudomonas and Xanthomonas species have two lexA genes, whose products have been shown to recognize different LexA binding motifs, making them an interesting target for studying the interplay between cohabiting LexA regulons in a single species. Here we report an analysis of(More)
BACKGROUND Integrons are found in hundreds of environmental bacterial species, but are mainly known as the agents responsible for the capture and spread of antibiotic-resistance determinants between Gram-negative pathogens. The SOS response is a regulatory network under control of the repressor protein LexA targeted at addressing DNA damage, thus promoting(More)
Staphylococcal superantigen-carrying pathogenicity islands (SaPIs) are discrete, chromosomally integrated units of approximately 15 kilobases that are induced by helper phages to excise and replicate. SaPI DNA is then efficiently encapsidated in phage-like infectious particles, leading to extremely high frequencies of intra- as well as intergeneric(More)