...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: Topological features and in vivo interactions
【24h】

Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: Topological features and in vivo interactions

机译：使用分裂泛素系统研究酵母寡糖基转移酶亚基：拓扑特征和体内相互作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Oligosaccharyl transferase (OT) catalyzes the cotranslational N-glycosylation of nascent polypeptides in the endoplasmic reticu-lum in all eukaryotic systems. Due to the inherent difficulty in characterizing this membrane protein complex, the mode of enzymatic action has not been resolved. Here, we used a membrane protein two-hybrid approach, the split-ubiquitin system, to address two aspects of the enzyme complex in yeast: the topological features, as well as the in vivo interactions of all of the components. We investigated the N- and C-terminal orientation of these proteins and the presence or the absence of a cleavable signal sequence at their N termini. We found that Ost2p and Stt3p have only their N terminus located in the cytosol, whereas Ost3p and Swp1p have only their C terminus oriented in the cytosol. In the case of Ost3p and Ost6p, both their N and C termini are present in the cytosol. These findings also suggested that Ost2p, Stt3p, Ost5p, and Ost6p do not have a cleavable N-terminal signal sequence. The pairwise analysis of in vivo interactions among all of the OT subunits demonstrated that OT subunits display specific interactions with each other in a functional complex. By comparing this interaction pattern with that detected in vitro in a nonfunctional complex, we proposed that a distinct conformation rearrangement takes place when the enzyme complex changes from the nonfunctional state to the activated functional state. This finding is consistent with earlier work by others indicating that OT exhibits allosteric properties.
机译：寡糖基转移酶（OT）催化所有真核系统内质网中新生多肽的共翻译N-糖基化。由于表征该膜蛋白复合物固有的困难，因此尚未解决酶促作用的模式。在这里，我们使用了膜蛋白两杂交法，即分裂泛素系统，来解决酵母中酶复合物的两个方面：拓扑特征以及所有组件的体内相互作用。我们研究了这些蛋白质的N和C末端方向，以及在其N末端是否存在可裂解的信号序列。我们发现，Ost2p和Stt3p仅在胞质溶胶中具有N末端，而Ost3p和Swp1p仅在胞质溶胶中具有C末端。就Ost3p和Ost6p而言，其N和C末端都存在于细胞质中。这些发现还表明，Ost2p，Stt3p，Ost5p和Ost6p没有可切割的N端信号序列。所有OT亚基之间的体内相互作用的成对分析表明，OT亚基在功能复合物中彼此显示特定的相互作用。通过将这种相互作用模式与在非功能性复合物中体外检测到的相互作用模式进行比较，我们提出了当酶复合物从非功能性状态变为活化功能性状态时发生独特的构象重排。这一发现与其他人先前的工作一致，表明OT具有变构特性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号