Genome-wide discovery of small RNAs in Mycobacterium tuberculosis

PLoS One. 2012;7(12):e51950. doi: 10.1371/journal.pone.0051950. Epub 2012 Dec 19.

Abstract

Only few small RNAs (sRNAs) have been characterized in Mycobacterium tuberculosis and their role in regulatory networks is still poorly understood. Here we report a genome-wide characterization of sRNAs in M. tuberculosis integrating experimental and computational analyses. Global RNA-seq analysis of exponentially growing cultures of M. tuberculosis H37Rv had previously identified 1373 sRNA species. In the present report we show that 258 (19%) of these were also identified by microarray expression. This set included 22 intergenic sRNAs, 84 sRNAs mapping within 5'/3' UTRs, and 152 antisense sRNAs. Analysis of promoter and terminator consensus sequences identified sigma A promoter consensus sequences for 121 sRNAs (47%), terminator consensus motifs for 22 sRNAs (8.5%), and both motifs for 35 sRNAs (14%). Additionally, 20/23 candidates were visualized by Northern blot analysis and 5' end mapping by primer extension confirmed the RNA-seq data. We also used a computational approach utilizing functional enrichment to identify the pathways targeted by sRNA regulation. We found that antisense sRNAs preferentially regulated transcription of membrane-bound proteins. Genes putatively regulated by novel cis-encoded sRNAs were enriched for two-component systems and for functional pathways involved in hydrogen transport on the membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5' Untranslated Regions
  • Cluster Analysis
  • Consensus Sequence
  • Gene Expression Profiling*
  • Gene Expression Regulation, Bacterial
  • Gene Regulatory Networks
  • Molecular Sequence Annotation
  • Mycobacterium tuberculosis / genetics*
  • Mycobacterium tuberculosis / metabolism
  • Nucleotide Motifs
  • RNA, Antisense / genetics
  • RNA, Antisense / metabolism
  • RNA, Bacterial / classification
  • RNA, Bacterial / genetics*
  • RNA, Bacterial / metabolism
  • Reproducibility of Results
  • Signal Transduction
  • Terminator Regions, Genetic

Substances

  • 5' Untranslated Regions
  • RNA, Antisense
  • RNA, Bacterial

Grants and funding

This work was partially supported by the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement FP7-223681 to DMC and from the European Society of Clinical Microbiology and Infectious Diseases Research Grant 2011 to PM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.