5-Hydroxy-2'-deoxyuridine (5-OHdU) is a major stable oxidation product of 2'-Deoxycytidine. 5-Hydroxy-2'-deoxyuridine can be incorporated into DNA in vitro by DNA polymerase[1].
To study the specificity of nucleotide incorporation opposite 5-hydroxypyrimidines in template DNA, 18- and 45-member oligodeoxyribonucleotides, containing an internal 2'-deoxy-5-hydroxyuridine (5-OHdU) in two different sequence contexts, were used. Translesion synthesis past 2'-deoxy-5-hydroxyuridine (5-OHdU) in both oligonucleotides occurred, but pauses both opposite, and one nucleotide prior to, the modified base in the template is observed. The specificity of nucleotide incorporation opposite 2'-deoxy-5-hydroxyuridine (5-OHdU) in the template is sequence context dependent. In one sequence context, dA is the principal nucleotide incorporated opposite 2'-deoxy-5-hydroxyuridine (5-OHdU). However in a second sequence context, dC is the predominant base incorporated opposite 2'-deoxy-5-hydroxyuridine (5-OHdU). In that same sequence context, dC is also the predominant nucleotide incorporated opposite 2'-deoxy-5-hydroxyuridine (5-OHdU)[1].
[1]. Purmal AA, et al. Major oxidative products of cytosine, 5-hydroxycytosine and 5-hydroxyuracil, exhibit sequence context-dependent mispairing in vitro. Nucleic Acids Res. 1994 Jan 11;22(1):72-8.