Structural basis for DNA 5´-end resection by RecJ

Autor: Kaiying Cheng, Hong Xu, Xuanyi Chen, Liangyan Wang, Bing Tian, Ye Zhao, Yuejin Hua
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: eLife, Vol 5 (2016)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.14294
Popis: The resection of DNA strand with a 5´ end at double-strand breaks is an essential step in recombinational DNA repair. RecJ, a member of DHH family proteins, is the only 5´ nuclease involved in the RecF recombination pathway. Here, we report the crystal structures of Deinococcus radiodurans RecJ in complex with deoxythymidine monophosphate (dTMP), ssDNA, the C-terminal region of single-stranded DNA-binding protein (SSB-Ct) and a mechanistic insight into the RecF pathway. A terminal 5´-phosphate-binding pocket above the active site determines the 5´-3´ polarity of the deoxy-exonuclease of RecJ; a helical gateway at the entrance to the active site admits ssDNA only; and the continuous stacking interactions between protein and nine nucleotides ensure the processive end resection. The active site of RecJ in the N-terminal domain contains two divalent cations that coordinate the nucleophilic water. The ssDNA makes a 180° turn at the scissile phosphate. The C-terminal domain of RecJ binds the SSB-Ct, which explains how RecJ and SSB work together to efficiently process broken DNA ends for homologous recombination.
Databáze: Directory of Open Access Journals