The effect of the 2-amino group of 7,8-dihydro-8-oxo-2'-deoxyguanosine on translesion synthesis and duplex stability.

ABSTRACT: Replication of DNA containing 7,8-dihydro-8-oxo-2'-deoxyguanosine (OxodG) gives rise to G --> T transversions. The syn-isomer of the lesion directs misincorporation of 2'-deoxyadenosine (dA) opposite it. We investigated the role of the 2-amino substituent on duplex thermal stability and in replication using 7,8-dihydro-8-oxo-2'-deoxyinosine (OxodI). Oligonucleotides containing OxodI at defined sites were chemically synthesized via solid phase synthesis. Translesion incorporation opposite OxodI was compared with 7,8-dihydro-8-oxo-2'-deoxyguanosine (OxodG), 2'-deoxyinosine (dI) and 2'-deoxyguanosine (dG) in otherwise identical templates. The Klenow exo- fragment of Escherichia coli DNA polymerase I incorporated 2'-deoxyadenosine (dA) six times more frequently than 2'-deoxycytidine (dC) oppos

SUBMITTER: Oka N 

PROVIDER: S-EPMC1067523 | biostudies-literature | 2005

REPOSITORIES: biostudies-literature