2017年5月
The mechanism of the glycosylase reaction with hOGG1 base-excision repair enzyme: concerted effect of Lys249 and Asp268 during excision of 8-oxoguanine
NUCLEIC ACIDS RESEARCH
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- 巻
- 45
- 号
- 9
- 開始ページ
- 5231
- 終了ページ
- 5242
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1093/nar/gkx157
- 出版者・発行元
- OXFORD UNIV PRESS
The excision of 8-oxoguanine (oxoG) by the human 8-oxoguanine DNA glycosylase 1 (hOGG1) base-excision repair enzyme was studied by using the QM/MM (M06-2X/6-31G(d,p): OPLS2005) calculation method and nuclear magnetic resonance (NMR) spectroscopy. The calculated glycosylase reaction included excision of the oxoG base, formation of Lys249-ribose enzyme-substrate covalent adduct and formation of a Schiff base. The formation of a Schiff base with Delta G(#) = 17.7 kcal/mol was the rate-limiting step of the reaction. The excision of the oxoG base with Delta G(#) = 16.1 kcal/mol proceeded via substitution of the C1'-N9 N-glycosidic bond with an H-N9 bond where the negative charge on the oxoG base and the positive charge on the ribose were compensated in a concerted manner by NH3+(Lys249) and CO2- (Asp268), respectively. The effect of Asp268 on the oxoG excision was demonstrated with H-1 NMR for WT hOGG1 and the hOGG1(D268N) mutant: the excision of oxoG was notably suppressed when Asp268 was mutated to Asn. The loss of the base-excision function was rationalized with QM/MM calculations and Asp268 was confirmed as the electrostatic stabilizer of ribose oxocarbenium through the initial base-excision step of DNA repair. The NMR experiments and QM/MM calculations consistently illustrated the base-excision reaction operated by hOGG1.
- リンク情報
- ID情報
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- DOI : 10.1093/nar/gkx157
- ISSN : 0305-1048
- eISSN : 1362-4962
- PubMed ID : 28334993
- Web of Science ID : WOS:000402064200028