Human NEIL3 is mainly a monofunctional DNA glycosylase removing spiroimindiohydantoin and guanidinohydantoin
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- 作者：Silje Z. Krokeide ; Jon K. Laerdahl ; Medya Salah ; Luisa Luna ; F. Henning Cederkvist ; Aaron M. Fleming ; Cynthia J. Burrows ; Bj酶rn Dalhus ; Magnar Bj酶r氓s
- 关键词：5OHC ; 5-hydroxy-2&prime ; -deoxycytidine ; 5OHU ; 5-hydroxy-2&prime ; -deoxyuridine ; AP ; apurinic/apyrimidinic ; BER ; base excision repair ; CV ; column volume ; faPy ; 2 ; 6-diamino-4-hydroxy-5-formamidopyrimidine ; Fpg ; Escherichia coli formamidopyrimidine DNA glycosylase ; GD ; core glycosylase domain ; Gh ; guanidinohydantoin ; H2TH ; helix-two-turn-helix ; MCS ; multiple cloning site ; Nei ; E. coli endonuclease VIII ; NEIL ; E. coli endonuclease VIII-like ; Nth ; endonuclease III ; ROS ; reactive oxygen species ; Sp ; sp
- 刊名：DNA Repair
- 出版年：December, 2013
- 年：2013
- 卷：12
- 期：12
- 页码：1159-1164
- 全文大小：994 K
文摘
Base excision repair is the major pathway for removal of oxidative DNA base damage. This pathway is initiated by DNA glycosylases, which recognize and excise damaged bases from DNA. In this work, we have purified the glycosylase domain (GD) of human DNA glycosylase NEIL3. The substrate specificity has been characterized and we have elucidated the catalytic mechanisms. GD NEIL3 excised the hydantoin lesions spiroiminodihydantoin (Sp) and guanidinohydantoin (Gh) in single-stranded (ss) and double-stranded (ds) DNA efficiently. NEIL3 also removed 5-hydroxy-2鈥?deoxycytidine (5OHC) and 5-hydroxy-2鈥?deoxyuridine (5OHU) in ssDNA, but less efficiently than hydantoins. Unlike NEIL1 and NEIL2, which possess a 尾,未-elimination activity, NEIL3 mainly incised damaged DNA by 尾-elimination. Further, the base excision and strand incision activities of NEIL3 exhibited a non-concerted action, indicating that NEIL3 mainly operate as a monofunctional DNA glycosylase. The site-specific NEIL3 mutant V2P, however, showed a concerted action, suggesting that the N-terminal amino group in Val2 is critical for the monofunctional modus. Finally, we demonstrated that residue Lys81 is essential for catalysis.