Biochemical characterization of two DNA ligases from Deinococcus radiodurans

Donghai Le, Xiaoting Hua, Lifen Huang, Guanjun Gao, Huiming Lu, Zhenjian Xu, Bing Tian, Yuejin Hua

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Two genes encoding a NAD+ -dependent DNA ligase (LigA) and an ATP-dependent DNA ligase (LigB) were identified in the genome of the extremely radioresistant bacterium, Deinococcus radiodurans (DR). The recombinant enzymes expressed in Escherichia coli, were purified to homogeneity and characterized. The optimal temperature and pH value of the two DNA ligases were 60 °C and 7.0, respectively. Their optimal concentration of MgCl2 was 5mM. Their half-lifes of heat inactivation at 100 °C were about 3 min and 5 min, respectively. In addition, the results showed that DRLigB displayed higher activity than DRLigA at stick and blunt ended joining of DNA, indicating that DRLigB is a key DNA ligase of D. radiodurans in DNA recombination and double-strand break repair.

Original languageEnglish (US)
Pages (from-to)600-605
Number of pages6
JournalProtein and Peptide Letters
Issue number6
StatePublished - Jul 1 2008


  • DNA ligase
  • DNA recombination
  • Deinococcus radiodurans
  • Double-strand break repair
  • Metal cofactor
  • Stick and blunt ended DNA ligation

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry


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