title: Modified pyrimidines specifically bind the purine riboswitch.
abstract: The purine riboswitch is a genetic regulatory element found in the 5'-untranslated regions of Gram-positive bacteria that regulates expression of the mRNA specifically in response to either guanine or adenine. We report that the adenine-responsive RNA element is also capable of specifically recognizing pyrimidine compounds bearing modifications at the 6- or 5,6-positions in a fashion similar to that of purine compounds. Using isothermal titration calorimetry and X-ray crystallography, the binding of these compounds is characterized.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado at Boulder, Campus Box 215, Boulder, Colorado 80309-0215, USA.
authors.forename: Sunny D
authors.initials: SD
authors.lastname: Gilbert
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Mediatore
authors.forename: Robert T
authors.initials: RT
authors.lastname: Batey
mesh_terms: D000225:Adenine / Q000737:chemistry; D020029:Base Pairing; D001665:Binding Sites; D018360:Crystallography, X-Ray; D006147:Guanine / Q000737:chemistry; D009690:Nucleic Acid Conformation; D011687:Purines / Q000737:chemistry* / Q000378:metabolism; D011743:Pyrimidines / Q000737:chemistry* / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D011687:Purines; D011743:Pyrimidines; D038621:Regulatory Sequences, Ribonucleic Acid; D006147:Guanine; D000225:Adenine; C030986:pyrimidine; C030985:purine