5f55

Publication Abstract from PubMed

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 degrees 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.

Structural basis for DNA 5 -end resection by RecJ.,Cheng K, Xu H, Chen X, Wang L, Tian B, Zhao Y, Hua Y Elife. 2016 Apr 8;5. pii: e14294. doi: 10.7554/eLife.14294. PMID:27058167^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.