A Bacterial Pathogen Flips the Riboswitch Bobbi Xayarath, Nancy E. Freitag  Cell Host & Microbe  Volume 6, Issue 5, Pages 400-402 (November 2009) DOI: 10.1016/j.chom.2009.10.009 Copyright © 2009 Elsevier Inc. Terms and Conditions

Figure 1 Model of SreA cis and trans Regulation (A) The SreA riboswitch is located immediately upstream of three genes, lmo2491-2418-2417. In the absence of the metabolite SAM, SreA forms an antitermination structure that allows transcription of the downstream genes. (B) Binding of SAM to SreA alters its formation and a terminator structure is formed, resulting in the production of a short transcript lacking the downstream genes. This small RNA is capable of binding the prfA mRNA at high temperature (37°C) leading to a reduction in PrfA protein synthesis. At low temperatures (≤30°C), the thermosensor element located in the 5′UTR of prfA mRNA prevents both SreA binding and prfA mRNA translation. Cell Host & Microbe 2009 6, 400-402DOI: (10.1016/j.chom.2009.10.009) Copyright © 2009 Elsevier Inc. Terms and Conditions