title: Non-hydrogen-bonded base pairs for specific transcription.
abstract: Specific transcription mediated by unnatural base pairs could create novel RNA molecules with increased functionality and expand the genetic code. Here, we report an unnatural base pair between pyrrole-2-carbaldehyde (Pa) and 2-amino-6-(2-thienyl)purine (s) or 6-(2-thienyl)purine (s') for the site-specific incorporation of s or s' into RNA by T7 RNA polymerase, using DNA templates containing Pa. Despite the absence of significant hydrogen bonding interactions between the unnatural bases, the efficiency and fidelity of the s-Pa pairing in transcription were as high as those of the natural base pairings. As shown in replication, this indicates the importance of shape complementarity between pairing bases in transcription. Since the s base is fluorescent, this transcription mediated by the s-Pa pair provides a useful tool for site-specific fluorescence probing of RNA molecules.
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hirao
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Mitsui
authors.forename: Michiko
authors.initials: M
authors.lastname: Kimoto
authors.forename: Rie
authors.initials: R
authors.lastname: Kawai
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D020029:Base Pairing; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D006860:Hydrogen Bonding; D011687:Purines / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D012313:RNA / Q000096:biosynthesis / Q000737:chemistry*; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism
chemical_list: C435686:2-amino-6-(2-thienyl)purine; D005456:Fluorescent Dyes; D011687:Purines; D011758:Pyrroles; D014764:Viral Proteins; C051266:pyrrole-2-carboxaldehyde; D012313:RNA; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases