The LexA regulated genes of the Clostridium difficile

BMC Microbiology

Research Article

Nejc Paulič¹  Vesna Hodnik¹  Matej Butala¹  Darja Žgur-Bertok¹  Gregor Anderluh²  Beata M Walter³  Maja Rupnik⁴  Bruno Dupuy⁵ 

[1]Biotechnical Faculty Department of Biology, University of Ljubljana, Ljubljana, Slovenia

[2]Biotechnical Faculty Department of Biology, University of Ljubljana, Ljubljana, Slovenia

[3]National Institute of Chemistry, Ljubljana, Slovenia

[4]Centre for Microbiology, Institute of Public Health Maribor, Maribor, Slovenia

[5]Centre for Microbiology, Institute of Public Health Maribor, Maribor, Slovenia

[6]Faculty of Medicine, University of Maribor, Maribor, Slovenia

[7]Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Ljubljana, Slovenia

[8]Laboratoire Pathogenèse des Bactéries Anaérobies, Département de Microbiologie, Institut Pasteur, Paris, France

关键词: Clostridium difficile;    Antibiotic resistance;    Toxin regulation;    SOS system;    Surface plasmon resonance;    LexA repressor;   

DOI  :  10.1186/1471-2180-14-88

 received in 2013-12-23, accepted in 2014-03-27,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe SOS response including two main proteins LexA and RecA, maintains the integrity of bacterial genomes after DNA damage due to metabolic or environmental assaults. Additionally, derepression of LexA-regulated genes can result in mutations, genetic exchange and expression of virulence factors. Here we describe the first comprehensive description of the in silico LexA regulon in Clostridium difficile, an important human pathogen.ResultsWe grouped thirty C. difficile strains from different ribotypes and toxinotypes into three clusters according to lexA gene/protein variability. We applied in silico analysis coupled to surface plasmon resonance spectroscopy (SPR) and determined 16 LexA binding sites in C. difficile. Our data indicate that strains within the cluster, as defined by LexA variability, harbour several specific LexA regulon genes. In addition to core SOS genes: lexA, recA, ruvCA and uvrBA, we identified a LexA binding site on the pathogenicity locus (PaLoc) and in the putative promoter region of several genes involved in housekeeping, sporulation and antibiotic resistance.ConclusionsResults presented here suggest that in C. difficile LexA is not merely a regulator of the DNA damage response genes but also controls the expression of dozen genes involved in various other biological functions. Our in vitro results indicate that in C. difficile inactivation of LexA repressor depends on repressor`s dissociation from the operators. We report that the repressor`s dissociation rates from operators differentiate, thus the determined LexA-DNA dissociation constants imply on the timing of SOS gene expression in C. difficile.

【 授权许可】

Unknown   
© Walter et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.