Restriction glycosylases: involvement of endonuclease activities in the restriction process

Yingbiao Zhang, Tomoyuki Matsuzaka, Hirokazu Yano, Yoshikazu Furuta, Toshiaki Nakano, Ken Ishikawa, Masaki Fukuyo, Noriko Takahashi, Yutaka Suzuki, Sumio Sugano, Hiroshi Ide, Ichizo Kobayashi

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


All restriction enzymes examined are phosphodiesterases generating 3΄-OH and 5΄-P ends, but one restriction enzyme (restriction glycosylase) excises unmethylated bases from its recognition sequence. Whether its restriction activity involves endonucleolytic cleavage remains unclear. One report on this enzyme, R.PabI from a hyperthermophile, ascribed the breakage to high temperature while another showed its weak AP lyase activity generates atypical ends. Here, we addressed this issue in mesophiles. We purified R.PabI homologs from Campylobacter coli (R.CcoLI) and Helicobacter pylori (R.HpyAXII) and demonstrated their DNA cleavage, DNA glycosylase and AP lyase activities in vitro at 37°C. The AP lyase activity is more coupled with glycosylase activity in R.CcoLI than in R.PabI. R.CcoLI/R.PabI expression caused restriction of incoming bacteriophage/plasmid DNA and endogenous chromosomal DNA within Escherichia coli at 37°C. The R.PabI-mediated restriction was promoted by AP endonuclease action in vivo or in vitro. These results reveal the role of endonucleolytic DNA cleavage in restriction and yet point to diversity among the endonucleases. The cleaved ends are difficult to repair in vivo, which may indicate their biological significance. These results support generalization of the concept of restriction–modification system to the concept of self-recognizing epigenetic system, which combines any epigenetic labeling and any DNA damaging.

Original languageEnglish
Pages (from-to)1392-1403
Number of pages12
JournalNucleic acids research
Issue number3
Publication statusPublished - 2017 Feb 17
Externally publishedYes

ASJC Scopus subject areas

  • Genetics


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