A novel endonuclease that may be responsible for damaged DNA base repair in Pyrococcus furiosus

Miyako Shiraishi, Sonoko Ishino, Takeshi Yamagami, Yuriko Egashira, Shinichi Kiyonari, Yoshizumi Ishino

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


DNA is constantly damaged by endogenous and environmental influences. Deaminated adenine (hypoxanthine) tends to pair with cytosine and leads to the A:T→G:C transition mutation during DNA replication. Endonuclease V (EndoV) hydrolyzes the second phosphodiester bond 3' from deoxyinosine in the DNA strand, and was considered to be responsible for hypoxanthine excision repair. However, the downstream pathway after EndoV cleavage remained unclear. The activity to cleave the phosphodiester bond 5' from deoxyinosine was detected in a Pyrococcus furiosus cell extract. The protein encoded by PF1551, obtained from the mass spectrometry analysis of the purified fraction, exhibited the corresponding cleavage activity. A putative homolog from Thermococcus kodakarensis (TK0887) showed the same activity. Further biochemical analyses revealed that the purified PF1551 and TK0887 proteins recognize uracil, xanthine and the AP site, in addition to hypoxanthine. We named this endonuclease Endonuclease Q (EndoQ), as it may be involved in damaged base repair in the Thermococcals of Archaea.

Original languageEnglish
Pages (from-to)2853-2863
Number of pages11
JournalNucleic acids research
Issue number5
Publication statusPublished - Mar 11 2015

All Science Journal Classification (ASJC) codes

  • Genetics


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