Recognition of HNA and 1,5-anhydrohexitol nucleotides by DNA metabolizing enzymes

Hexitol nucleic acids (HNA) as well as their 1,5-anhydrohexitol triphosphate building blocks were evaluated for their ability to be recognized by several DNA metabolizing enzymes. It was found that RNA polymerases can recognize the triphosphate of the adenine analogue. However, only the incorporation of a maximum of three consecutive building block analogues was possible under the applied experimental conditions. Terminal transferase was more successful succeeding in the elongation of a DNA primer with a maximum of 15 1,5-anhydrohexitol purine nucleotides. Furthermore, it was observed that the 1,5-anhydroaltritol triphosphate analogue of adenosine was a poor substrate for terminal transferase and that HNA could not act as a primer for this enzyme. Likewise, HNA did not function as a template for restriction enzymes, ligases or methylases.