Differential discrimination of DNA polymerase for variants of the non-standard nucleobase pair between xanthosine and 2,4-diaminopyrimidine, two components of an expanded genetic alphabet.

AUTOR(ES)

Lutz, M J

RESUMO

Mammalian DNA polymerases alpha and epsilon, the Klenow fragment of Escherichia coli DNA polymerase I and HIV-1 reverse transcriptase (RT) were examined for their ability to incorporate components of an expanded genetic alphabet in different forms. Experiments were performed with templates containing 2'-deoxyxanthosine (dX) or 2'-deoxy-7-deazaxanthosine (c7dX), both able to adopt a hydrogen bonding acceptor-donor-acceptor pattern on a purine nucleus (puADA). Thus these heterocycles are able to form a non-standard nucleobase pair with 2,4-diaminopyrimidine (pyDAD) that fits the Watson-Crick geometry, but is joined by a non-standard hydrogen bonding pattern. HIV-1 RT incorporated d(pyDAD)TP opposite dX with a high efficiency that was largely independent of pH. Specific incorporation opposite c7dX was significantly lower and also independent of pH. Mammalian DNA polymerases alpha and epsilon from calf thymus and the Klenow fragment from E. coli DNA polymerase I failed to incorporate d(pyDAD)TP opposite c7dX.

Documentos Relacionados

• The Family X DNA Polymerase from Deinococcus radiodurans Adopts a Non-standard Extended Conformation
• A non-standard optimal control problem arising in an economics application
• PCR amplification of DNA containing non-standard base pairs by variants of reverse transcriptase from Human Immunodeficiency Virus-1
• V(D)J recombination intermediates and non-standard products in XRCC4-deficient cells.
• A quarter of the medical jobs advertised in the NHS are for non-standard posts