1. Epigenetic DNA modification N6-methyladenine inhibits DNA replication by Sulfolobus solfataricus Y-family DNA polymerase Dpo4.
- Author
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Du, Ke, Zhang, Shuming, Chen, Weina, Dai, Mengyuan, Xu, Zhongyan, Liang, Tingting, Huang, Wenxin, Ling, Yihui, and Zhang, Huidong
- Subjects
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DNA polymerases , *DNA , *PHYSIOLOGICAL control systems , *EPIGENETICS , *DNA replication , *DNA primers - Abstract
Dpo4 is a representative model of Y-family DNA polymerase and is therefore one of the most intensively studied DNA polymerase. 6 mA, an epigenetic marker, plays important roles in regulation of various biological processes. However, its effects on DNA replication by Dpo4 is completely unknown. Here, we found that 6 mA and its intermediate Hyp inhibits primer extension by Dpo4, showing an obvious blockage just one nucleotide before 6 mA or Hyp. 6 mA reduces dTTP incorporation efficiency, next-base extension efficiency, binding affinity of DNA to Dpo4, binding affinity of dTTP to Dpo4-DNA complex, the fraction of productive Dpo4 or productive ternary complex, and the burst incorporation rate, explaining the inhibition effects of 6 mA on DNA replication by Dpo4. Hyp is similar to G and dCTP is preferentially incorporated opposite Hyp by Dpo4, resulting in A:T to G:C mutation. Relative to dTTP incorporation opposite unmodified A, Hyp reduces dCTP incorporation efficiency, next-base extension efficiency, the priority in extension beyond correct pair, binding affinity of Dpo4 to DNA, binding of dCTP to Dpo4-DNA complex, and the burst incorporation efficiency, explaining the inhibition effects of Hyp on DNA replication by Dpo4. This work provides insight in the effects of epigenetically modified 6 mA and Hyp on DNA replication by a representative Y-family DNA polymerase Dpo4. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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