Difilippantonio M J, McMahan C J, Eastman Q M, Spanopoulou E, Schatz D G
Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520-8011, USA.
Cell. 1996 Oct 18;87(2):253-62. doi: 10.1016/s0092-8674(00)81343-4.
Recent studies have demonstrated that DNA cleavage during V(D)J recombination is mediated by the RAG1 and RAG2 proteins. These proteins must therefore bind to the recombination signals, but the specific binding interaction has been difficult to study in vitro. Here, we use an in vivo one-hybrid DNA binding assay to demonstrate that RAG1, in the absence of RAG2, can mediate signal recognition via the nonamer, with the heptamer acting to enhance its binding. A region of RAG1 with sequence similarity to bacterial invertases is essential for DNA binding. Localization of RAG2 to the signal is dependent upon the presence of RAG1 and is substantially more efficient with a 12 bp spacer signal than with a 23 bp spacer signal.
最近的研究表明，V(D)J重组过程中的DNA切割是由RAG1和RAG2蛋白介导的。因此，这些蛋白必须与重组信号结合，但这种特异性结合相互作用在体外很难研究。在这里，我们使用体内单杂交DNA结合试验来证明，在没有RAG2的情况下，RAG1可以通过九聚体介导信号识别，七聚体则起到增强其结合的作用。RAG1中与细菌转化酶具有序列相似性的区域对于DNA结合至关重要。RAG2定位于信号依赖于RAG1的存在，并且对于12 bp间隔信号比对23 bp间隔信号的定位效率要高得多。
