STEAROTHERMOPHILUS RIBOSOMAL PROTEIN L11 & 23S RNA FRAGMENT THERMODYNAMICS

对蛋白质-核酸相互作用驱动力的认识 酸相互作用需要热力学参数的知识 由每个物种贡献。在两个“刚体” 缔合，络合物的热容与 粘合时的溶剂化反应产生的非极性表面积。然而， 当这种相互作用导致局部构象变化时 蛋白质，额外的非极性表面也可能被掩埋 影响CP(联想)。斯波尔和唱片(科学，1994 263：777)建立了一个热力学模型来描述 蛋白质-脱氧核糖核酸复合体之间的相互作用。而当 蛋白质和RNA之间的复合体已经被很好地记录下来，以及 热力学参数的穷尽热力学分析 这种相互作用并不适用于这些系统。这个 原核生物核糖体蛋白L11与58碱基的相互作用 ~(23)S rRNA区域是一个很好的模型系统 这个热力学模型。展开的热力学表明， RRNA片段在生理温度范围内稳定。 其结合域的L11溶液结构显示出显著的 与DNA螺旋-旋转-螺旋超家族的结构同源性 结合蛋白。等温滴定量热法实验将 以确定交互的CP(关联)。 这些实验以及核磁共振结构信息 结合和未结合的蛋白质将提供信息 提高我们对蛋白质-RNA的能量学的理解 互动。

The understanding of the driving forces mediating protein-nucleic acid interaction requires knowledge of the thermodynamic parameters contributed by each species. In the case where two "rigid bodies" associate, the heat capacity of complex formation is related to the amount of nonpolar surface area from solvation upon binding. However, when such an interaction causes local conformational changes to the protein, additional nonpolar surfaces may also be buried thereby affecting the Cp (association). Spolar and Record (Science 1994 263:777) have established a thermodynamic model to describe the interaction between protein-deoxyribonucleic acid complexes. While complexes between protein and RNA have been well documented, an exhaustive thermodynamic analyses of the thermodynamic parameters of such an interaction have not been applies to these systems. The interaction between the prokaryotic ribosomal protein L11 and a 58 nt. region of 23S rRNA is an excellent model system for the application of this thermodynamic model. The unfolding thermodynamics show that the rRNA fragment in stabile within the physiological temperature range. The L11 solution structure of its binding domain shows remarkable structural homology with the helix-turn-helix superfamily of DNA binding proteins. Isothermal Titration Calorimetry experiments will be conducted to determine the Cp (association) of the interaction. These experiments along with the NMR structure information of the bound and unbound protein will provide information to improve our understanding of the energetics of protein-RNA interaction.