Genome wide analysis of the complete GlnR nitrogen-response regulon in Mycobacterium smegmatis

BMC Genomics

Research Article

Geraint R Barton¹  Victoria A Jenkins²  Kerstin J Williams²  Brian D Robertson³ 

[1] Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, SW7 2AZ, South Kensington, London, UK;MRC Centre for Molecular Bacteriology and Infection, Imperial College London, SW7 2AZ, South Kensington, London, UK;MRC Centre for Molecular Bacteriology and Infection, Imperial College London, SW7 2AZ, South Kensington, London, UK;Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, SW7 2AZ, South Kensington, London, UK;

关键词: Nitrogen Metabolism;    Nitrogen Limitation;    Nitrogen Excess;    Mycobacterium Smegmatis;    Ammonium Transporter;   

DOI  :  10.1186/1471-2164-14-301

 received in 2013-03-01, accepted in 2013-04-29,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundNitrogen is an essential element for bacterial growth and an important component of biological macromolecules. Consequently, responding to nitrogen limitation is critical for bacterial survival and involves the interplay of signalling pathways and transcriptional regulation of nitrogen assimilation and scavenging genes. In the soil dwelling saprophyte Mycobacterium smegmatis the OmpR-type response regulator GlnR is thought to mediate the transcriptomic response to nitrogen limitation. However, to date only ten genes have been shown to be in the GlnR regulon, a vastly reduced number compared to other organisms.ResultsWe investigated the role of GlnR in the nitrogen limitation response and determined the entire GlnR regulon, by combining expression profiling of M. smegmatis wild type and glnR deletion mutant, with GlnR-specific chromatin immunoprecipitation and high throughput sequencing. We identify 53 GlnR binding sites during nitrogen limitation that control the expression of over 100 genes, demonstrating that GlnR is the regulator controlling the assimilation and utilisation of nitrogen. We also determine a consensus GlnR binding motif and identify key residues within the motif that are required for specific GlnR binding.ConclusionsWe have demonstrated that GlnR is the global nitrogen response regulator in M. smegmatis, directly regulating the expression of more than 100 genes. GlnR controls key nitrogen stress survival processes including primary nitrogen metabolism pathways, the ability to utilise nitrate and urea as alternative nitrogen sources, and the potential to use cellular components to provide a source of ammonium. These studies further our understanding of how mycobacteria survive nutrient limiting conditions.

【 授权许可】

Unknown   
© Jenkins et al.; licensee BioMed Central Ltd. 2013. 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 cited.