Correlation between physical stability map and genetic map of DNA double strand

本项目旨在揭示DNA分子线的物理稳定性图与遗传图之间的相关性。作为物理稳定性图，我们研究了B-A跃迁和螺旋-线圈跃迁的物理稳定性。用微机控制微弹的多维分光光度计研究了ColE1 DNA在高浓度乙醇作用下的B-A跃迁。过渡比长度较短的可选共聚物更宽，并且在限制片段之间变化。这些事实提供了第一个证据，证明B-A过渡的稳定性沿着长DNA双链变化。将双螺旋稳定性分布与基因在大量dna中的位置进行比较，揭示了“基因同质稳定倾向”，即每个蛋白质编码区在其自身特征值周围具有均匀稳定性分布的趋势。发现这种倾向是通过同义密码子的使用获得的。利用摆动三碱基的冗余来抵消由密码子第一碱基和第二碱基引起的局域G+C含量变化。

The purpose of this project is to reveal the correlation between physical stability map and genetic map of the DNA molecular thread. As the physical stability map, we have studied those in the B-A transition and the helix-coil transition.The B-A transition of ColE1 DNA caused by high ethanol concentrations has been studied by the multi-dimensional spectrophotometer equipped with the computer-controlled microbullet. The transition is broader than that of alternative copolymers with shorter lengths and varies among restriction fragments. These facts have provided the first evidence to prove that the stability in the B-A transition varies along a long DNA double strand.Comparison between the double-helix stability distribution and the location of genes in a large number of DNAs has disclosed the "gene homostabilizing propensity": the tendency for each protein coding region to have a uniform stability distribution around its own characteristic value. The propensity was found to be attained by the synonymous codon usage. The redundancy at the wobble third base is utilized to counterbalance the local G+C content variation due to the first and second bases of codons.