The dNaM (BA0343) and d5SICS (BA0344) matched pair appears to be a very interesting novel base pair, achieving pair recognition through hydrophobic interactions that rivals the A-T and G-C pairing in the natural genetic alphabet.⁽¹⁾ In addition, they have been shown to be well-replicated by DNA polymerases under steady-state conditions, regardless of sequence. The fidelity and efficiency of dNaM and d5SICS replication approach those of natural synthesis. Both dNaM and d5SICS are also efficiently transcribed by T7 RNA polymerase in either direction. In 2009, the Romesberg and Marx groups reported data that showed KlenTaq polymerase induces the dNaM-d5SICS unnatural base pair to adopt a natural Watson-Crick like strucutre.⁽²⁾

Ref:

1. (a) Seo, Y.J.; Matsuda, S.; Romesberg, F.E. J. Am. Chem. Soc., 2009, 131, 5046-7. (b) Seo, Y.J.; Hwang, G.T.; Ordoukhanian, P.; Romesberg, F.E. J. Am. Chem. Soc., 2009, 131, 3246-52. (c) Seo, Y.J.; Romesberg, F.E. ChemBioChem, 2009, 10, 2394-2400. (d) Hwang, G.T.; Hari, Y.; Romesberg, F.E. Nucleic Acids Res., 2009, 37, 4757-63. (e) Hari, Y.; Hwang, G.T.; Leconte, A.M.; Joubert, N.; Hocek, M.; Romesberg, F.E. ChemBioChem, 2008, 9, 2796-9. (f) Hwang, G.T.; Romesberg, F.E. J. Am. Chem. Soc., 2008, 130, 14872-82. (g) Leconte, A.M.; Hwang, G.T.; Matsuda, S.; Capek, P.; Hari, Y.; Romesberg, F.E J. Am. Chem. Soc., 2008, 130, 2336-43.
2. Betz, K.; Malyshev, D.A.; Lavergne, T.; Welte, W.; Diederichs, K.; Dwyer, T.J.; Ordoukhanian, P.; Romesberg, F.E.; Marx, A. Nat. Chem. Biol. 2012, 8, 612-614.