Magnesium controls aptamer-expression platform switching in the SAM-I riboswitch

Simple item page
dc.citation.firstpage3158en_US
dc.citation.issueNumber6en_US
dc.citation.journalTitleNucleic Acids Researchen_US
dc.citation.lastpage3170en_US
dc.citation.volumeNumber47en_US
dc.contributor.authorRoy, Susmitaen_US
dc.contributor.authorHennelly, Scott P.en_US
dc.contributor.authorLammert, Heikoen_US
dc.contributor.authorOnuchic, José Nelsonen_US
dc.contributor.authorSanbonmatsu, Karissa Y.en_US
dc.date.accessioned2019-12-11T15:44:15Zen_US
dc.date.available2019-12-11T15:44:15Zen_US
dc.date.issued2019en_US
dc.description.abstractInvestigations of most riboswitches remain confined to the ligand-binding aptamer domain. However, during the riboswitch mediated transcription regulation process, the aptamer domain and the expression platform compete for a shared strand. If the expression platform dominates, an anti-terminator helix is formed, and the transcription process is active (ON state). When the aptamer dominates, transcription is terminated (OFF state). Here, we use an expression platform switching experimental assay and structure-based electrostatic simulations to investigate this ON-OFF transition of the full length SAM-I riboswitch and its magnesium concentration dependence. Interestingly, we find the ratio of the OFF population to the ON population to vary non-monotonically as magnesium concentration increases. Upon addition of magnesium, the aptamer domain pre-organizes, populating the OFF state, but only up to an intermediate magnesium concentration level. Higher magnesium concentration preferentially stabilizes the anti-terminator helix, populating the ON state, relatively destabilizing the OFF state. Magnesium mediated aptamer-expression platform domain closure explains this relative destabilization of the OFF state at higher magnesium concentration. Our study reveals the functional potential of magnesium in controlling transcription of its downstream genes and underscores the importance of a narrow concentration regime near the physiological magnesium concentration ranges, striking a balance between the OFF and ON states in bacterial gene regulation.en_US
dc.identifier.citationRoy, Susmita, Hennelly, Scott P., Lammert, Heiko, et al.. "Magnesium controls aptamer-expression platform switching in the SAM-I riboswitch." <i>Nucleic Acids Research,</i> 47, no. 6 (2019) Oxford University Press: 3158-3170. https://doi.org/10.1093/nar/gky1311.en_US
dc.identifier.digitalgky1311en_US
dc.identifier.doihttps://doi.org/10.1093/nar/gky1311en_US
dc.identifier.urihttps://hdl.handle.net/1911/107842en_US
dc.language.isoengen_US
dc.publisherOxford University Pressen_US
dc.rightsThis work is written by (a) US Government employee(s) and is in the public domain in the US.en_US
dc.titleMagnesium controls aptamer-expression platform switching in the SAM-I riboswitchen_US
dc.typeJournal articleen_US
dc.type.dcmiTexten_US
dc.type.publicationpublisher versionen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
gky1311.pdf
Size:
2.96 MB
Format:
Adobe Portable Document Format
Download
Collections
Faculty Publications
BioSciences Publications
Chemistry Publications
Physics and Astronomy Publications