Now available for use in RNA synthesis is 2-thiouridine CEPwith 2’-TBS protection. It is postulated that, prior to the evolution of ribozymes, non-enzymatic replication of RNA played an important genetic role in primitive life forms. The greater thermodynamic stability of the modified Watson-Crick (s2U)-A base pair compared to omnipresent U-A base pair- has been found to enhance the fidelity of non-enzymatic RNA primer extension. It is interesting to speculate on the possible roles that s2U may have historically played in primitive organisms lacking the capability for enzymatic RNA replication. Given the observations in non-enzymatic RNA replication, it is quite logical that the fidelity of ribozyme-catalyzed RNA primer extension has also been found to be enhanced by the incorporation of s2Uand s2T (2-thio-ribo-thymidine). While U is clearly modern-day’s preferred A basepair partner, the availability of s2U and its phosphoramidite provide powerful tools for further scientific exploration of RNA replication and RNA duplex stability.

Substitution with sulfur at the 2-position of uridine provides a tool for the investigation of RNA duplex stability⁽¹⁾ and non-enzymatic⁽²⁾ and ribozyme catalyzed RNA primer extension.⁽³⁾

Ref:

1. (a) Kumar, R.K.; Davis, D.R. Nuc. Acid. Res. 1997, 25(6), 1272-1280. (b) Testa, S.M.; Disney, M.D.; Turner, D.H.; Kierzek, R. Biochem. 1999, 38, 16655-16662.
2. Heuberger, B.D.; Pal, A.; Del Frate, F.; Topkar, V.V.; Szostak, J.W. J. Am. Chem. Soc., 2015, 137 (7), pp 2769–2775.
3. Prywes, N.; Michaels, Y.S.; Pal, A.; Oh, S.S., Szostak, J.W. Chem. Commun. 2016. 52, 6529-6532.