Bacterial small RNA

Bacterial small RNAs (sRNA) are small RNAs produced by bacteria; they are 50- to 500-nucleotide non-coding RNA molecules, highly structured and containing several stem-loops. Numerous sRNAs have been identified using both computational analysis and laboratory-based techniques such as Northern blotting, microarrays and RNA-Seq in a number of bacterial species including Escherichia coli, the model pathogen Salmonella, the nitrogen-fixing alphaproteobacterium Sinorhizobium meliloti, marine cyanobacteria,Francisella tularensis (the causative agent of tularaemia),, the pathogen Staphylococcus aureus, and the plant pathogen Xanthomonas oryzae pathovar oryzae. Bacterial sRNAs effect how genes are expressed within bacterial cells via interaction with mRNA or protein, and thus can effect a variety of bacterial functions like metabolism, virulence, environmental stress response, and structure.

In the 1960s, the abbreviation sRNA was used to refer to "soluble RNA," which is now known as transfer RNA or tRNA (for an example of the abbreviation used in this sense, see). It is now known that most bacterial sRNAs are encoded by free-standing genes located in the intergenic regions (IGR) between two known genes. However, a class of sRNAs are shown to be derived from the 3'-UTR of mRNAs by independent transcription or nucleolytic cleavage.

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