An unnatural base pair system for in vitro replication and transcription.

Ichiro Hirao, Michiko Kimoto, Tsuneo Mitsui, Tsuyoshi Fujiwara, Rie Kawai, Akira Sato, Yoko Harada, Shigeyuki Yokoyama

Index: Nucleic Acids Symp. Ser. (50) , 33-4, (2006)

Full Text: HTML

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.