An Efficient Unnatural Base Pair for a Base-Pair-Expanded Transcription System

摘要

For the site-specific incorporation of artificial components into RNA by transcription,an efficient,unnatural base pair between 2-amino-6-(2-thiazolyl)purine (denoted as v) and 2-oxo(1 H)pyridine (denoted as y) was developed.The substrates of y and 5-substituted y were site-specifically incorporated into RNA by T7 RNA polymerase opposite v in templates.The efficiency and fidelity of the v-y pairing in transcription were as high as those of the natural A-T(U) and G-C pairings.Furthermore,RNAs containing two adjacent y bases were also transcribed from DNA templates containing two v bases.This specific transcription allows the large-scale preparation of artificial RNAs and can be combined with other systems to simultaneously incorporate several different components into a transcript.