植物线粒体和质体双定位蛋白质的带电特性分析

蛋白质亚细胞定位分析是揭示蛋白质功能的关键步骤。1个蛋白质分子能被定位到2个亚细胞位置,这一现象被称为蛋白质的"双定位"。本研究首先从Uniprot、MitoP2、MGI、TAIR、DBMLoc等蛋白质数据库及已发表文献中收集双定位于线粒体与质体的植物蛋白质数据,共获得703个双定位蛋白质,组成测试数据集。再从Uniprot数据库中选取唯一定位于线粒体的829个和唯一定位于质体的6 376个植物蛋白质,组成参照数据集,分析双定位于线粒体与质体的植物蛋白质的带电特征。结果表明,与单定位于线粒体或质体的植物蛋白质相比,双定位线粒体与质体的植物蛋白质具有更低的净电荷量;此外,双定位蛋白质电荷分布较为集中对称,线粒体蛋白质次之,质体蛋白质最为分散。本文研究结果将为揭示植物蛋白质双定位的分子机制奠定理论基础。

Net Electric Charges of Dual Targeted Proteins in Mitochondria and Plastid of Plants

Protein targeting is an important tool to determine the functionality of a protein.Adual targeted protein isa protein that located in two subcellular locations.It was estimated that more than 400 proteins were putatively targeted to mitochondria as well as plastid based on the ambiguous N-terminal pre-sequences in land plant genomes. In this study,the dual targeted proteins were searched against the protein databases of Uniprot,Mito P2,MGI, TAIR,and DBMLoc as well as the existing publications.A total of 703 proteins localized in both mitochondria and plastid in plants were collected.Whilst,829 exclusive mitochondrial and 6 376 exclusive plastid proteins were downloaded from Uniprotfor comparison.The net electric charges of the dual targeted proteins were analyzed based on these 3 data sets.The results indicated the net charge of the plant dual targeted proteins was significantly lower than that of the proteins exclusively existed in mitochondrial or plastid.The charge differentiation provideda critical clue for the study of the molecular mechanism of dual targeted proteins in plants.