Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Premature terminator analysis sheds light on a hidden world of bacterial transcriptional attenuation. | Naville and Gautheret Genome Biology 2010 11 R97 http 2010 11 9 R97 Genome Biology RESEARCH Open Access Premature terminator analysis sheds light on a hidden world of bacterial transcriptional attenuation Magali Naville Daniel Gautheret Abstract Background Bacterial transcription attenuation occurs through a variety of cis-regulatory elements that control gene expression in response to a wide range of signals. The signal-sensing structures in attenuators are so diverse and rapidly evolving that only a small fraction have been properly annotated and characterized to date. Here we apply a broad-spectrum detection tool in order to achieve a more complete view of the transcriptional attenuation complement of key bacterial species. Results Our protocol seeks gene families with an unusual frequency of 5 terminators found across multiple species. Many of the detected attenuators are part of annotated elements such as riboswitches or T-boxes which often operate through transcriptional attenuation. However a significant fraction of candidates were not previously characterized in spite of their unmistakable footprint. We further characterized some of these new elements using sequence and secondary structure analysis. We also present elements that may control the expression of several non-homologous genes suggesting co-transcription and response to common signals. An important class of such elements which we called mobile attenuators is provided by 3 terminators of insertion sequences or prophages that may be exapted as 5 regulators when inserted directly upstream of a cellular gene. Conclusions We show here that attenuators involve a complex landscape of signal-detection structures spanning the entire bacterial domain. We discuss possible scenarios through which these diverse 5 regulatory structures may arise or evolve. Background Transcription of protein-coding genes does not always lead to the production of full length mRNAs. In both eukaryotes and .
