Identification and functional characterization of bacterial small non-coding RNAs and their target: A review

A large number of bacterial small non-coding RNAs (sRNAs) have been identified in the past few years. These are known as heterogeneous group of molecules that act by different mechanisms to modulate a wide range of physiological responses. Many of the identified sRNAs, ranging in size from 40 to 500 nucleotides in length, are highly conserved, located in intergenic regions, and/or in-between open reading frames. Functional studies revealed that sRNAs interact with their target mRNAs by antisense mechanisms, usually around their translation start sites, to modulate gene expression at the posttranscriptional level. Although the number of known sRNAs has dramatically increased in recent years, many challenges in the identification and characterization of sRNAs lie ahead. Here, we review the common strategies used for identification of bacterial sRNAs and their mRNA targets, as well as their functional characterization using experimental approaches which will facilitate our understanding of sRNA biology.