中文摘要：

利用本实验室前期以ATP6为诱饵蛋白，通过酵母双杂交系统筛选到的一个N端含有RINGv结构（RING—variant）的蛋白，暂命名为BnRCH，构建GTK—BnRCH表达载体在原核细胞E．coliBL21（DE3）中高效表达GST—BnRCH融合蛋白，并将纯化的融合蛋白加入体外泛素反应体系，发现BnRCH在ATP、泛素、E1、E2存在的条件下，能催化多聚泛素化形成，具有E3连接酶活性．

英文摘要：

ATP6 was used as the bait protein to screen its interacting partners by yeast two-hybrid system. Then a fragment, which has a RINGv （RING-variant） structure, was therefore found, and we ten- tatively named it BnRCH. BnRCH from Brassica napus was cloned into the prokaryotic expression vector GTK to express BnRCH as a glutathione-s-transferase （GST） fusion protein. The recombinant ex- pression plasmid was then transformed into E. coli BL21 （DE3）. In the presence of human E1 and human E2, ubiquitination activity was observed in the presence of purified GST-BnRCH, indicating that BnRCH has E3 ligase activity in vitro.