2008年11月
Crystal Structure of MutS2 Endonuclease Domain and the Mechanism of Homologous Recombination Suppression
JOURNAL OF BIOLOGICAL CHEMISTRY
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- 巻
- 283
- 号
- 48
- 開始ページ
- 33417
- 終了ページ
- 33427
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1074/jbc.M806755200
- 出版者・発行元
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DNA recombination events need to be strictly regulated, because an increase in the recombinational frequency causes unfavorable alteration of genetic information. Recent studies revealed the existence of a novel anti-recombination enzyme, MutS2. However, the mechanism by which MutS2 inhibits homologous recombination has been unknown. Previously, we found that Thermus thermophilus MutS2 (ttMutS2) harbors an endonuclease activity and that this activity is confined to the C-terminal domain, whose amino acid sequence is widely conserved in a variety of proteins with unknown function from almost all organisms ranging from bacteria to man. In this study, we determined the crystal structure of the ttMutS2 endonuclease domain at 1.7-angstrom resolution, which resembles the structure of the DNase I-like catalytic domain of Escherichia coli RNase E, a sequence-nonspecific endonuclease. The N-terminal domain of ttMutS2, however, recognized branched DNA structures, including the Holliday junction and D-loop structure, a primary intermediate in homologous recombination. The full-length of ttMutS2 digested the branched DNA structures at the junction. These results indicate that ttMutS2 suppresses homologous recombination through a novel mechanism involving resolution of early intermediates.
- リンク情報
- ID情報
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- DOI : 10.1074/jbc.M806755200
- ISSN : 0021-9258
- PubMed ID : 18838375
- Web of Science ID : WOS:000261183700046