Abstract
In the nonhomologous end joining pathway of DNA double-strand break repair, the ligation step is catalyzed by a complex of XRCC4 and DNA ligase IV. Extracts of CHO-K1 cells are able to accurately rejoin a site-specific free radical-mediated double-strand break with partially complementary overhangs, by a mechanism involving alignment-based gap filling followed by ligation. Extracts of XR-1 cells, which lack XRCC4 and DNA ligase IV, carried out neither gap filling nor ligation. Supplementation of the extracts with recombinant XRCC4/ligase IV, but not with XRCC4 alone, restored gap filling and accurate end joining. The results imply that XRCC4 and ligase IV are essential for alignment-based gap filling, as well as for final ligation of the breaks.
Original language | English (US) |
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Pages (from-to) | 22-24 |
Number of pages | 3 |
Journal | Cancer research |
Volume | 63 |
Issue number | 1 |
State | Published - Jan 1 2003 |
ASJC Scopus subject areas
- Oncology
- Cancer Research