Ribonucleosides for an artificially expanded genetic information system.

ABSTRACT

Rearranging hydrogen bonding groups adds nucleobases to an artificially expanded genetic information system (AEGIS), pairing orthogonally to standard nucleotides. We report here a large-scale synthesis of the AEGIS nucleotide carrying 2-amino-3-nitropyridin-6-one (trivially Z) via Heck coupling and a hydroboration/oxidation sequence. RiboZ is more stable against epimerization than its 2'-deoxyribo analogue. Further, T7 RNA polymerase incorporates ZTP opposite its Watson-Crick complement, imidazo[1,2-a]-1,3,5-triazin-4(8H)one (trivially P), laying grounds for using this "second-generation" AEGIS ZP pair to add amino acids encoded by mRNA.