Phylogenetic analysis of the Tic20 genefamily.

This dataset contains a multi sequence alignemt of Tic20 homologues from 59 differnt species from cyanobacteria, red- and green algae and landplants. Tic20 is a polytopic protein of the inner envelope membrane of chloroplasts, and it is proposed to act as a translocation channel during chloroplast protein import. By analyzing 29 sequences from diverse organisms, it was evident that Tic20-related proteins form two distinct clades, termed Group 1 and Group 2. The former group includes canonical Tic20 proteins that are essential for chloroplast development, while members of the latter are of unknown function. An increased evolutionary rate, in connection with adaptation to terrestrial life, was detected in Group 1. Interestingly, the sub-cellular (genomic) localization of genes coding for Group 1 proteins differs between evolutionary lineages.

本数据集包含来自蓝细菌、红藻、绿藻以及陆地植物共59个不同物种的Tic20同源蛋白（Tic20 homologues）的多序列比对（multiple sequence alignment）。Tic20是叶绿体内被膜的多次跨膜蛋白，被认为在叶绿体蛋白导入过程中发挥转运通道的作用。通过分析来自不同生物的29条序列，研究表明Tic20相关蛋白可形成两个独立的进化支，分别命名为组1（Group 1）与组2（Group 2）。前者包含对叶绿体发育至关重要的经典Tic20蛋白，而后者成员的功能尚未明确。研究检测到组1蛋白的进化速率有所提升，这与陆生生活适应存在关联。值得注意的是，编码组1蛋白的基因的亚细胞（基因组）定位在不同进化谱系中存在差异。