For citation purposes: Ternan NG. Small regulatory RNA molecules in bacteria. OA Microbiology 2013 Dec 01;1(1):1.


Genetics & Molecular Biology

Small regulatory RNA molecules in bacteria

NG Ternan

Authors affiliations

Northern Ireland Centre for Food and Health, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland

* Corresponding author Email:



Small non-coding RNA molecules are widespread in all kingdoms of life, where they serve to regulate and fine-tune gene expression. They can act in cis or trans, depending upon their structural relationship with genes whose expression they influence and function by interacting with target messenger RNA molecules to inhibit or accelerate translation. Thus, they can exert rapid control on cellular protein levels. Within bacteria, many small RNAs have been described in Gram-negative model organisms, but developments in our understanding of their role in Gram-positive organisms have been slower. It is clear that small RNAs (sRNAs) influence a wide range of cellular processes, including adaptation to environmental stresses, and virulence processes in pathogens. The aim of this review was to discuss the key elements of sRNA biology and to summarise what is known of their role in Clostridia.


Historically, identification of small RNAs has been challenging but recent developments in sequencing technology and computational analysis have led to over 45,000 predicted small RNAs being catalogued in the past few years. However, many of these in silico predictions are yet to be validated and the complexity, in terms of small RNA interactions with gene networks, means we are really only beginning to understand how wide-ranging their effects can be within bacteria. It is clear that small RNAs play a critical role in all aspects of bacterial physiology. Within the genus Clostridium, the role of small RNAs in the pathogens Clostridium perfringens, Clostridium botulinum and Clostridium difficile is much less well understood, despite hundreds of small RNAs having been predicted within these organisms.


RNOmics is a rapidly expanding field and it is clear that advances in our understanding must deploy high-throughput post-genomic technologies such RNA sequencing in efforts to determine the functions of individual bacterial sRNAs. Using in silico predictions as a platform for novel discoveries, it will be of interest to determine the conditions under which sRNAs are expressed, and whether strain to strain variations exist. The research community now has an opportunity to identify, and consequently to define the roles of, sRNAs within these microorganisms.

Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)