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Metnase possesses a structure‐specific endonuclease activity that enhances joining of non‐compatible ends
Author(s) -
Lee SukHee,
Hromas Robert,
Oshige Masahiko,
Lee Sue S
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb38
Subject(s) - endonuclease , transposase , dna , microbiology and biotechnology , dna repair , non homologous end joining , biology , chemistry , in vitro , mutant , transposable element , genetics , gene
Metnase (SETMAR) is a SET and transposase fusion protein that promotes non‐homologous end joining (NHEJ) repair in humans. Although both the SET and the transposase domains were necessary for its function in DSB repair, it is not clear what specific role Metnase plays in the NHEJ. In this study, we show that Metnase possesses a structure‐specific endonuclease activity that preferentially acts on ssDNA and ssDNA‐overhang of a partial duplex DNA. Cell extracts lacking Metnase barely supported DNA end joining. An addition of wt‐Metnase to cell extracts lacking Metnase fully restored DNA end joining activity, while a mutant lacking endonuclease activity failed to restore DNA end joining both in vivo and in vitro NHEJ repair. Further in vitro analysis indicated that Metnase has a facilitating role in the processing of non‐compatible ends. Together, our findings support a positive role for Metnase's endonuclease activity in promoting joining of non‐compatible DNA ends.