title: An unnatural base pair system for in vitro replication and transcription.
abstract: The development of unnatural base pairs that function in replication, transcription, and translation could expand the genetic alphabet and enable the site-specific incorporation of functional components into nucleic acids and proteins. We present an unnatural base pair between 7-(2-thienyl)-imidazo[4,5-b]pyridine (denoted by Ds) and pyrrole-2-carbaldehyde (denoted by Pa). In replication, the Ds-Pa pair exhibits high selectivity in combination with the usual and modified triphosphate substrates and exonuclease-proficient DNA polymerases. In transcription, the Ds-Pa pair mediates the site-specific incorporation of the substrates of both Ds and Pa into RNA by T7 RNA polymerase. This unnatural base pair system could facilitate the specific incorporation of functional components into RNA molecules at desired positions using DNA templates containing the unnatural base pair, which can be amplified by PCR.
authors.affiliation: Protein Research Group, RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hirao
authors.forename: Michiko
authors.initials: M
authors.lastname: Kimoto
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Mitsui
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Rie
authors.initials: R
authors.lastname: Kawai
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.forename: Yoko
authors.initials: Y
authors.lastname: Harada
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D020029:Base Pairing; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D011743:Pyrimidines / Q000737:chemistry* / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry* / Q000378:metabolism; D013698:Templates, Genetic; D013876:Thiophenes / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism
chemical_list: C522077:7-(2-thienyl)imidazo(4,5-b)pyrimidine; D011743:Pyrimidines; D011758:Pyrroles; D013876:Thiophenes; D014764:Viral Proteins; C051266:pyrrole-2-carboxaldehyde; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases; D004259:DNA-Directed DNA Polymerase