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A multifunctional DNA polymerase I involves in the maturation of Okazaki fragments during the lagging‐strand DNA synthesis in Helicobacter pylori
Author(s) -
Cheng YiWen,
Chen ChengYao
Publication year - 2021
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.15434
Subject(s) - okazaki fragments , dna polymerase ii , dna polymerase , dna clamp , dna replication , dna polymerase i , dna polymerase delta , biology , primase , microbiology and biotechnology , primer (cosmetics) , circular bacterial chromosome , dna ligase , eukaryotic dna replication , dna , chemistry , genetics , rna , gene , reverse transcriptase , organic chemistry
Helicobacter pylori is the most infectious human pathogen that causes gastritis, peptic ulcers and stomach cancer. H. pylori DNA polymerase I (HpPol I) is found to be essential for the viability of H. pylori , but its intrinsic property and attribution to the H. pylori DNA replication remain unclear. HpPol I contains a 5′→3′ exonuclease (5′‐Exo) and DNA polymerase (Pol) domain, respectively, but lacks a 3′→5′ exonuclease, or error proofreading activity. In this study, we characterized the 5′‐Exo and Pol functions of HpPol I and found that HpPol I is a multifunctional protein displaying DNA nick translation, strand‐displacement synthesis, RNase H‐like, structure‐specific endonuclease and exonuclease activities. In the in vitro DNA replication assay, we further demonstrated that the 5′‐Exo and Pol domains of HpPol I can cooperate to fill in the DNA gap, remove the unwanted RNA primer from a RNA/DNA hybrid and create a ligatable nick for the DNA ligase A of H. pylori to restore the normal duplex DNA. Altogether, our study suggests that the two catalytic domains of HpPol I may synergistically play an important role in the maturation of Okazaki fragments during the lagging‐strand DNA synthesis in H. pylori . Like the functions of DNA polymerase I in Escherichia coli , HpPol I may involve in both DNA replication and repair in H. pylori.