Liu Yilun, Masson Jean-Yves, Shah Rajvee, O'Regan Paul, West Stephen C
Cancer Research UK, London Research Institute, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, UK.
Science. 2004 Jan 9;303(5655):243-6. doi: 10.1126/science.1093037.
During genetic recombination and the recombinational repair of chromosome breaks, DNA molecules become linked at points of strand exchange. Branch migration and resolution of these crossovers, or Holliday junctions (HJs), complete the recombination process. Here, we show that extracts from cells carrying mutations in the recombination/repair genes RAD51C or XRCC3 have reduced levels of HJ resolvase activity. Moreover, depletion of RAD51C from fractionated human extracts caused a loss of branch migration and resolution activity, but these functions were restored by complementation with a variety of RAD51 paralog complexes containing RAD51C. We conclude that the RAD51 paralogs are involved in HJ processing in human cells.
在基因重组和染色体断裂的重组修复过程中，DNA分子在链交换点处相连。这些交叉点（即霍利迪连接体，HJs）的分支迁移和拆分完成了重组过程。在此，我们表明，携带重组/修复基因RAD51C或XRCC3突变的细胞提取物中HJ拆分酶活性水平降低。此外，从分级分离的人细胞提取物中去除RAD51C会导致分支迁移和拆分活性丧失，但通过与多种含有RAD51C的RAD51旁系同源复合物互补，这些功能得以恢复。我们得出结论，RAD51旁系同源物参与人类细胞中的HJ处理。
