...
  • 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 >Molecular dissection of the roles of nucleotide binding and hydrolysis in dynein's AAA domains in Saccharomyces cerevisiae
【24h】

Molecular dissection of the roles of nucleotide binding and hydrolysis in dynein's AAA domains in Saccharomyces cerevisiae

机译：酿酒酵母中动力蛋白的AAA结构域中核苷酸结合和水解作用的分子解剖

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

The motor protein cytoplasmic dynein is responsible for most of the minus-end-directed microtubule traffic within cells. Dynein contains four evolutionarily conserved AAA (ATPase associated with various cellular activities) domains that are thought to bind nucleotide; the role of nucleotide binding and hydrolysis in each of these four AAA domains has constituted an important and unresolved question in understanding dynein's mechanism. Using Sac-charomyces cerevisiae cytoplasmic dynein as a model system, we mutagenized residues involved in nucleotide binding or hydrolysis in the four AAA domains and examined the ability of the mutant dyneins to mediate nuclear segregation in vivo and to bind micro-tubules in vitro. Our analysis shows that an AAA1 hydrolysis mutant blocks dynein function, whereas a triple AAA2/3/4 hydrolysis mutant does not, suggesting that nucleotide binding is required at only one site. We also show that nucleotide binding at AAA3, but not hydrolysis, is essential for motor activity in vivo and ATP-induced dissociation of dynein from microtubules, suggesting that this domain acts as a critical allosteric site. In contrast, mutations in AAA2 cause subtle defects in dynein function, whereas mutation in AAA4 produce no obvious defects. These results show that the four conserved dynein AAA domains have distinct functions in dynein's mechanochemical cycle.
机译：运动蛋白胞质动力蛋白负责细胞内负端定向的微管运输。动力蛋白包含四个进化上保守的AAA（与各种细胞活动相关的ATPase）结构域，它们被认为与核苷酸结合。核苷酸结合和水解在这四个AAA结构域中的每一个中的作用已成为理解动力蛋白机理的重要且尚未解决的问题。使用酿酒酵母细胞质动力蛋白作为模型系统，我们诱变了四个AAA域中参与核苷酸结合或水解的残基，并研究了突变动力蛋白在体内介导核分离和在体外结合微管的能力。我们的分析表明，AAA1水解突变体可阻止动力蛋白的功能，而三重AAA2 / 3/4水解突变体则不能，这表明核苷酸结合仅需要一个位点。我们还显示，核苷酸结合在AAA3，而不是水解，对于体内的运动活动和ATP诱导的动力蛋白从微管的解离是必不可少的，这表明该结构域充当了关键的变构位点。相反，AAA2中的突变会导致动力蛋白功能发生细微的缺陷，而AAA4中的突变则不会产生明显的缺陷。这些结果表明，四个保守的动力蛋白AAA结构域在动力蛋白的机械化学循环中具有不同的功能。

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