Incorporation of 8-hydroxyguanosine (8-oxo-7,8-dihydroguanosine) 5'-triphosphate by bacterial and human RNA polymerases

作者：Kamiya Hiroyuki^*; Suzuki Akihiro; Yamaguchi Yuki; Handa Hiroshi; Harashima Hideyoshi

来源：Free Radical Biology and Medicine, 2009, 46(12): 1703-1707.

DOI：10.1016/j.freeradbiomed.2009.04.005

• Oxidized ribonucleotide
• 8-Hydroxyguanosine 5 '-triphosphate
• RNA polymerase
• Transcription
• Free radicals

Oxidized RNA precursors formed in the nucleotide pool may be incorporated into RNA. In this study, the incorporation of 8-hydroxyguanosine 5'-triphosphate (8-OH-GTP; 8-oxo-7,8-dihydroguanosine 5'-triphosphate) into RNA by Escherichia coli RNA polymerase was examined in Vitro, using a primer RNA and a template DNA with defined sequences. 8-OH-GTP was incorporated opposite C and A in the template DNA. Surprisingly, 8-OH-GTP was quite efficiently incorporated by the bacterial RNA polymerase, in contrast to the incorporation of the 2'-deoxyribo counterpart by DNA polymerases, as indicated by the kinetic parameters. The primer was further extended by the addition of a ribonucleotide complementary to the nucleobase adjacent to C or A (the nucleobase opposite which 8-OH-GTP was inserted). Thus, the incorporation of 8-OH-GTP did not completely inhibit further RNA chain elongation. 8-OH-GTP was also incorporated opposite C and A by human RNA polymerase II. These results suggest that 8-OH-GTP in the nucleotide pool call cause the formation of oxidized RNA and disturb the transmittance of genetic information.

• 出版日期2009-6-15