Epigenetic DNA modification N6-methyladenine inhibits DNA replication by Sulfolobus solfataricus Y-family DNA polymerase Dpo4.
Arch Biochem Biophys
; 675: 108120, 2019 10 30.
Article
in En
| MEDLINE
| ID: mdl-31563510
ABSTRACT
Dpo4 is a representative model of Y-family DNA polymerase and is therefore one of the most intensively studied DNA polymerase. 6â¯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 6â¯mA and its intermediate Hyp inhibits primer extension by Dpo4, showing an obvious blockage just one nucleotide before 6â¯mA or Hyp. 6â¯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 6â¯mA on DNA replication by Dpo4. Hyp is similar to G and dCTP is preferentially incorporated opposite Hyp by Dpo4, resulting in AT to GC 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 6â¯mA and Hyp on DNA replication by a representative Y-family DNA polymerase Dpo4.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
DNA
/
Adenine
/
Epigenesis, Genetic
/
Sulfolobus solfataricus
/
DNA-Directed DNA Polymerase
/
DNA Replication
Language:
En
Journal:
Arch Biochem Biophys
Year:
2019
Document type:
Article
Affiliation country:
China