The Saccharomyces cerevisiae Mus81-Mms4 complex is a highly conserved DNA structure-specific endonuclease that plays essential roles in the processing of recombination intermediates that arise during the repair of stalled replication forks and double-stranded breaks. To identify novel factors functioning conjointly with Mus81-Mms4, we performed a biochemical screen and found that Crp1, a cruciform DNA-recognizing protein that specifically binds to DNA four-way junction structures, could stimulate the Mus81-Mms4 endonuclease. The specific protein interaction between Mus81-Mms4 and Crp1 was responsible for the stimulation observed. Multi-copy expression of Crp1 could partially rescue the sensitivity to DNA damaging agents of the sgs1∆mus81∆21-24N mutant. Our results provide insight into the functional role and interaction of Crp1 with other proteins involved in DNA repair.

中文翻译：

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十字形 DNA 结合蛋白 Crp1 刺激酿酒酵母中 Mus81-Mms4 的核酸内切酶活性

Saccharomyces cerevisiae Mus81-Mms4 复合物是一种高度保守的 DNA 结构特异性核酸内切酶，在修复停滞的复制叉和双链断裂期间出现的重组中间体的处理中起重要作用。为了确定与 Mus81-Mms4 共同发挥作用的新因素，我们进行了生化筛选，发现 Crp1（一种十字形 DNA 识别蛋白，与 DNA 四向连接结构特异性结合）可以刺激 Mus81-Mms4 核酸内切酶。Mus81-Mms4 和 Crp1 之间的特定蛋白质相互作用是观察到的刺激的原因。Crp1 的多拷贝表达可以部分挽救 sgs1∆mus81∆21-24N 突变体对 DNA 损伤剂的敏感性。