mRNA环结构对蛋白质折叠速率的影响

前期的相关研究发现mRNA二级结构中存在对蛋白质折叠速率的重要影响因素.而mRNA二级结构中普遍存在着各种复杂的环结构,这些环结构是否对蛋白质折叠速率也有重要的影响呢?不同的环结构对蛋白质折叠速率的影响是否相同呢?基于此想法,建立了一个包含mRNA内部环、发夹环、膨胀环和多分支环等环结构信息和相应蛋白质折叠速率的数据库.对于数据库中的每一个蛋白质,计算了mRNA二级结构中各种环结构碱基含量、配对碱基含量及单链碱基含量等参量,分析了各参量与相应蛋白质折叠速率的相关性.结果显示,各种环结构碱基含量与蛋白质折叠速率均呈极显著或显著正相关.说明mRNA环结构对蛋白质折叠速率有重要的影响.进一步,把蛋白质按照不同折叠类型或不同二级结构类型分组后,对每一组蛋白质重复上述的分析工作.结果表明,对不同类蛋白质,mRNA的各种环结构对其相应蛋白质折叠速率的影响存在着显著差异.上述研究将为进一步开展有关mRNA和蛋白质折叠速率的研究奠定理论基础.

Influences of The mRNA Loop Structures on Protein Folding Rate

The important factors in secondary structures of mRNA influencing on protein folding rates are found during our previous research, and there are kinds of complex loop structures in secondary structures of mRNA. Do these complex loop structures have important influences on protein folding rate? Do different loop structures have similar effects on protein folding rate? Based on this idea, a data set that contains both the information of internal loops, hairpin loops, bulge loops, multi-branch loops and protein folding rates was constructed. For each protein in the data set, the secondary structures of mRNA were predicted followed by calculations of the parameters of mRNA secondary structures, including the base content of each loop structure, the content of base pairs, and the base content of the single strand. Analyses of the relationship between the protein folding rates and each parameter of loop structures of mRNA reveal that the protein folding rate has a significant positive correlation with the content of each kind of the four loop structures, it means that the loop structures of mRNA act as a kind of influential factors for the protein folding rate. Given the proteins in the data set were classed into different folding types and different secondary structural types, the relationship analyses reveal that for proteins in different types, the effects of loop structures on protein folding rate are significantly different. This work will provide the theoretical basis for the future study of mRNA and protein folding rate.