Metal ions-triggered polymerase activity and Its use for the development of molecular logic gates

We described a new strategy in which a polymerase enzyme is controlled to accomplish an unnatural extension reaction even at the mismatched site of a primer with template DNA. The validity of this novel concept was systematically demonstrated by using metal ions (Hg²⁺ and A^g+) to intentionally trigger an unusual polymerase activity at respective T-T and C-C mismatched primers on the basis of their specific interactions with the respective mismatched base pairs (T-T and C-C). A novel strategy to construct molecular scale logic gates was also developed based on the unnatural polymerase activity induced by metal ions. The successful operation of the key logic gates was demonstrated by rationally designing primers and employing metal ions (Hg²⁺ and A^g+) as inputs. In addition, this new concept could be applied to the development of a molecular translator, which could generate the functional nucleic acids such as aptamers and deoxyribozymes.