• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >ENERGETICS OF COUPLED TWIST AND WRITHE CHANGES IN CLOSED CIRCULAR PSM1 DNA
【24h】

ENERGETICS OF COUPLED TWIST AND WRITHE CHANGES IN CLOSED CIRCULAR PSM1 DNA

机译：闭合的圆形PSM1 DNA扭曲和扭曲变化的能量学

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 extent of local denaturation in closed circular pSM1 DNA depends upon the linking differences, Delta Lk, and the temperature, t. We have determined the denaturation profiles, using gel electrophoresis, over the ranges -37 less than or equal to Delta Lk less than or equal to +16 and 25 degrees C less than or equal to t less than or equal to 65 degrees C. We have applied statistical mechanical methods to these data to evaluate the free energies of superhelix formation, of the twisting of single strands around each other, and of the initration of local denaturation. Because the complete nucleotide sequence is needed for this analysis, the complete pSM1 DNA sequence was determined and is reported here. The values of the free energy parameters found in this work agree closely with those previously obtained from experiments with pBR322 DNA, suggesting that there is little dependence of these values on the particular DNA sequence. We find the temperature dependence of these free energies by the appropriate statistical mechanical analysis of the temperature-dependent denaturation profiles produced by supercoiling. Calculations of the transition probability profiles indicate that the course of local denaturation in pSM1 DNA involves a complex competition among several sites of comparable susceptibility This contrasts with the melting of pBR322 DNA, in which one principal site dominates. In both molecules the sites of predicted denaturation occur at or near regulatory regions, suggesting that duplex destabilization may be associated with their biological activities. (C) 1995 Academic Press Limited [References: 34]
机译：封闭的环状pSM1 DNA中的局部变性程度取决于连接差异Delta Lk和温度t。我们已经使用凝胶电泳在-37小于或等于Delta Lk小于或等于+16的范围内和25摄氏度下小于或等于t的温度小于或等于65摄氏度的范围内确定了变性曲线。已将统计机械方法应用于这些数据，以评估超螺旋形成，单链彼此缠绕以及局部变性引发的自由能。由于此分析需要完整的核苷酸序列，因此确定了完整的pSM1 DNA序列，并在此处报告。这项工作中发现的自由能参数值与先前从pBR322 DNA实验中获得的值非常吻合，表明这些值对特定DNA序列的依赖性很小。通过对超螺旋产生的温度依赖性变性曲线的适当统计力学分析，我们发现了这些自由能的温度依赖性。跃迁几率分布图的计算表明，pSM1 DNA的局部变性过程涉及多个具有相似敏感性的位点之间的复杂竞争。这与pBR322 DNA的熔解相反，在熔解中，一个主要位点占主导地位。在这两个分子中，预测的变性位点发生在调控区或调控区附近，这表明双链不稳定可能与其生物学活性有关。 （C）1995 Academic Press Limited [参考文献：34]

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