...
  • 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 >The evolutionary origin of the protein-translocating channel of chloroplastic envelope membranes: Identification of a cyanobacterial homolog
【24h】

The evolutionary origin of the protein-translocating channel of chloroplastic envelope membranes: Identification of a cyanobacterial homolog

机译：叶绿体包膜膜蛋白转运通道的进化起源：蓝细菌同系物的鉴定

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 known envelope membrane proteins of the chloroplastic protein import apparatus lack sequence similarity to proteins of other eukaryotic or prokaryotic protein transport systems. However, we detected a putative homolog of the gene encoding Toc75, the protein-translocating channel from the outer envelope membrane of pea chloro- plasts, in the genome of the cyanobacterium Synechocystis sp. PCC 6803. We investigated whether the low sequence identity of 21 reflects a structural and functional relationship be- tween the two proteins. We provide evidence that the cya- nobacterial protein is also localized in the outer membrane. From this information and the similarity of the predicted secondary structures, we conclude that Toc75 and the cya- nobacterial protein, referred to as SynToc75, are structural homologs. synToc75 is essential, as homozygous null mutants were not recovered after directed mutagenesis. Sequence analysis indicates that SynToc75 belongs to a family of outer membrane proteins from Gram-negative bacteria whose func- tion is not yet known. However, we demonstrate that these proteins are related to a specific group of prokaryotic secre- tion channels that transfer virulence factors, such as hemo- lysins and adhesins, across the outer membrane.
机译：叶绿体蛋白导入装置的已知包膜蛋白缺乏与其他真核或原核蛋白转运系统蛋白的序列相似性。然而，我们在蓝藻Synechocystis sp。的基因组中检测到编码Toc75的基因的推定同源物，Toc75是豌豆叶绿体外膜的蛋白质转运通道。 PCC6803。我们调查了21的低序列同一性是否反映了这两种蛋白之间的结构和功能关系。我们提供的证据表明，抗菌素蛋白也位于外膜中。根据这些信息和预测的二级结构的相似性，我们得出结论，Toc75和称为SynToc75的蓝细菌蛋白是结构同源物。 synToc75是必不可少的，因为纯合的无效突变体在定向诱变后无法恢复。序列分析表明，SynToc75属于革兰氏阴性细菌外膜蛋白家族，其功能尚不清楚。但是，我们证明了这些蛋白质与特定的原核分泌通道群相关，这些通道将毒力因子（例如溶血素和黏附素）转移到外膜上。

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