Abstract：
Su(Hw) belongs to the class of proteins that organize chromosome architecture, determine promoter activity, and participate in formation of the boundaries/insulators between the regulatory domains. This protein contains a cluster of 12 zinc fingers of the C2H2 type, some of which are responsible for binding to the consensus site. The Su(Hw) protein forms complex with the Mod(mdg4)-67.2 and the CP190 proteins, where the last one binds to all known Drosophila insulators. To further study functioning of the Su(Hw)-dependent complexes, we used the previously described su(Hw)E8 mutation with inactive seventh zinc finger, which produces mutant protein that cannot bind to the consensus site. The present work shows that the Su(Hw)E8 protein continues to directly interact with the CP190 and Mod(mdg4)-67.2 proteins. Through interaction with Mod(mdg4)-67.2, the Su(Hw)E8 protein can be recruited into the Su(Hw)-dependent complexes formed on chromatin and enhance their insulator activity. Our results demonstrate that the Su(Hw) dependent complexes without bound DNA can be recruited to the Su(Hw) binding sites through the specific protein-protein interactions that are stabilized by Mod(mdg4)-67.2.
摘要：
Su（Hw）属于组织染色体结构的蛋白质类别，确定启动子活性，并参与调控域之间的边界/绝缘体的形成。这种蛋白质含有12个C2H2型锌指簇，其中一些负责约束共识网站。Su（Hw）蛋白与Mod（mdg4）-67.2和CP190蛋白形成复合物，最后一个与所有已知的果蝇绝缘体结合。为了进一步研究Su（Hw）依赖性复合物的功能，我们使用之前描述的su（Hw）E8突变与无活性的第七锌指，产生不能与共有位点结合的突变蛋白。本工作表明Su(Hw)E8蛋白继续直接与CP190和Mod(mdg4)-67.2蛋白相互作用。通过与Mod（mdg4）-67.2的相互作用，可以将Su（Hw）E8蛋白募集到染色质上形成的Su（Hw）依赖性复合物中，并增强其绝缘子活性。我们的结果表明，没有结合DNA的Su（Hw）依赖性复合物可以通过Mod（mdg4）-67.2稳定的特定蛋白质-蛋白质相互作用募集到Su（Hw）结合位点。
