• 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 >Evolutionary stability of DNA uptake signal sequences in the Pasteurellaceae
【24h】

Evolutionary stability of DNA uptake signal sequences in the Pasteurellaceae

机译：巴氏杆菌科中DNA摄取信号序列的进化稳定性

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 DNA-uptake signal sequence (USS) of the bacterium Haemophilus influenzae is highly over-rep resented in its genome (1,471 copies of the core sequence AAGTGCGGT), and DNA fragments containing USS are preferentially taken up by competent cells. Because this bias favors uptake of conspecific DNA, USSs are often considered a kind of mate recognition system in bacteria, acting as species-specific barriers against uptake of unrelated DNA. However, the H. influenzae USS is highly over-rep resented in the genomes of three otherwise-divergent Pasteurellaceae species (Pasteurella multocida, Haemophilus somnus, and Actinobacillus actinomycetemcomitans, 927, 1,205, and 1,760 copies, respectively), suggesting that USSs do not always limit exchange. USSs in all these genomes are mainly in coding regions and show no orientation bias around the chromosome, weakening proposed USS functions in transcription termination and chromosome replication. Alignment of homologous genes was used to determine evolutionary relationships between individual USSs. Most H. influenzae USSs were found to have perfect or imperfect homologs (USS at the same location) in at least one other species, and most USSs in the other species had perfect or imperfect homologs in H. influenzae. These homologies suggest that the use of a common USS is due to inheritance of the USS-based uptake system from a common ancestor of the Pasteurellaceae, and it indicates that individual USSs can be evolutionarily stable elements of their genomes. The pattern is consistent with a molecular drive model of USS evolution, with new USSs arising by mutation and preferentially spread to new genomes by the biased DNA-uptake system. [References: 42]
机译：流感嗜血杆菌的DNA摄取信号序列（USS）在其基因组中表达率很高（核心序列AATGGCGGT的1,471拷贝），含有USS的DNA片段优先被感受态细胞摄取。由于这种偏向有利于吸收特定的DNA，因此USS通常被认为是细菌中的一种配偶识别系统，可作为物种特异性的屏障来阻止无关DNA的吸收。但是，流感嗜血杆菌USS在三种不同的巴斯德氏菌属（多杀巴斯德氏菌，嗜血杆菌和放线放线杆菌（分别为927、1205和1760个拷贝））的基因组中存在高度重复的现象，这表明USS没有总是限制交换。所有这些基因组中的USS主要位于编码区，并且在染色体周围没有方向偏向，从而削弱了USS在转录终止和染色体复制中的功能。同源基因的比对用于确定各个USS之间的进化关系。发现大多数流感嗜血杆菌USS在至少一个其他物种中具有完美或不完美的同源物（USS在同一位置），而其他物种中的大多数USS在流感嗜血杆菌中具有完美或不完美的同源物。这些同源性表明，通用USS的使用是由于巴斯德氏菌的共同祖先继承了基于USS的摄取系统，这表明单个USS可能是其基因组的进化稳定元件。这种模式与USS进化的分子驱动模型是一致的，新的USS是由突变产生的，并通过有偏向的DNA吸收系统优先扩散到新的基因组中。 [参考：42]

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