title: Tandem riboswitch architectures exhibit complex gene control functions.
abstract: Riboswitches are structured RNAs typically located in the 5' untranslated regions of bacterial mRNAs that bind metabolites and control gene expression. Most riboswitches sense one metabolite and function as simple genetic switches. However, we found that the 5' region of the Bacillus clausii metE messenger RNA includes two riboswitches that respond to S-adenosylmethionine and coenzyme B12. This tandem arrangement yields a composite gene control system that functions as a two-input Boolean NOR logic gate. These findings and the discovery of additional tandem riboswitch architectures reveal how simple RNA elements can be assembled to make sophisticated genetic decisions without involving protein factors.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, Post Office Box 208103, New Haven, CT 06520-8103, USA.
authors.forename: Narasimhan
authors.initials: N
authors.lastname: Sudarsan
authors.forename: Ming C
authors.initials: MC
authors.lastname: Hammond
authors.forename: Kirsten F
authors.initials: KF
authors.lastname: Block
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Welz
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Barrick
authors.forename: Adam
authors.initials: A
authors.lastname: Roth
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Breaker
mesh_terms: D020121:5' Untranslated Regions / Q000378:metabolism*; D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism; D001407:Bacillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D001483:Base Sequence; D003038:Cobamides / Q000378:metabolism* / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008024:Ligands; D008715:Methionine / Q000096:biosynthesis / Q000494:pharmacology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D020121:5' Untranslated Regions; D052157:Aptamers, Nucleotide; D003038:Cobamides; D008024:Ligands; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012436:S-Adenosylmethionine; D008715:Methionine; C000913:cobamamide