Yus, EvaGüell Cargol, Marc, 1982-Vivancos Prellezo, AnaChen, Wei-HuaLluch-Senar, Maria 1982-Delgado Blanco, JavierGavin, Anne-ClaudeBork, PeerSerrano Pubull, Luis, 1982-2014-04-292014-04-292012Yus E, Güell M, Vivancos AP, Chen WH, Lluch-Senar M, Delgado J et al. Transcription start site associated RNAs in bacteria. Mol Syst Biol. 2012; 8:585. DOI: 10.1038/msb.2012.161744-4292http://hdl.handle.net/10230/22229Here, we report the genome-wide identification of small RNAs associated with transcription start sites (TSSs), termed tssRNAs, in Mycoplasma pneumoniae. tssRNAs were also found to be present in a different bacterial phyla, Escherichia coli. Similar to the recently identified promoter-associated tiny RNAs (tiRNAs) in eukaryotes, tssRNAs are associated with active promoters. Evidence suggests that these tssRNAs are distinct from previously described abortive transcription RNAs. ssRNAs have an average size of 45 bases and map exactly to the beginning of cognate full-length transcripts and to cryptic TSSs. Expression of bacterial tssRNAs requires factors other than the standard RNA polymerase holoenzyme. We have found that the RNA polymerase is halted at tssRNA positions in vivo, which may indicate that a pausing mechanism exists to prevent transcription in the absence of genes. These results suggest that small RNAs associated with TSSs could be a universal feature of bacterial transcription.application/pdfengThis is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial Share Alike LicenseRNAMicrobiologiainfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/msb.2012.16info:eu-repo/semantics/openAccess