Kiianitsa Konstantin, Solinger Jachen A, Heyer Wolf-Dietrich
Sections of Microbiology and Molecular and Cellular Biology, Center for Genetics and Development, University of California-Davis, Davis, CA 95616-8665.
Proc Natl Acad Sci U S A. 2006 Jun 27;103(26):9767-72. doi: 10.1073/pnas.0604240103. Epub 2006 Jun 19.
Rad54 protein is a Snf2-related dsDNA-specific ATPase essential for homologous recombination mediated by Rad51 protein, the eukaryotic RecA ortholog. Snf2-related enzymes couple ATP hydrolysis with translocation on dsDNA to remodel or dissociate a wide variety of protein-dsDNA complexes. Rad54 and Rad51 interact through species-specific contacts and mutually stimulate their biochemical activities. Specifically, Rad51 bound to dsDNA, the product of homologous recombination after DNA-strand exchange, stimulates the Rad54 ATPase up to 6-fold, leading to the turnover of Rad51 in the product complex. Electron microscopy visualized the Rad51-Rad54 interaction on dsDNA, showing that an oligomeric form of Rad54 associates preferentially with termini of the Rad51-dsDNA filament. Our data support a mechanism of processive dsDNA-Rad51 filament dissociation by the translocating Rad54 protein.
Rad54蛋白是一种与Snf2相关的双链DNA特异性ATP酶,对于由真核生物RecA直系同源物Rad51蛋白介导的同源重组至关重要。与Snf2相关的酶将ATP水解与双链DNA上的移位偶联,以重塑或解离多种蛋白质-双链DNA复合物。Rad54和Rad51通过物种特异性接触相互作用,并相互刺激它们的生化活性。具体而言,与双链DNA结合的Rad51(DNA链交换后同源重组的产物)可将Rad54 ATP酶活性刺激高达6倍,导致产物复合物中Rad51的周转。电子显微镜观察到双链DNA上的Rad51-Rad54相互作用,表明Rad54的寡聚形式优先与Rad51-双链DNA细丝的末端结合。我们的数据支持了移位的Rad54蛋白导致双链DNA-Rad51细丝进行性解离的机制。