Department of Bioinformatics, Technische Universität München, Wissenschaftszentrum Weihenstephan, Freising, Germany.
Institute for Information Transmission Problems (Kharkevich Institute), RAS, Moscow, Russia.
Genome Biol Evol. 2018 Mar 1;10(3):928-938. doi: 10.1093/gbe/evy049.
Can orthologous proteins differ in terms of their ability to be secreted? To answer this question, we investigated the distribution of signal peptides within the orthologous groups of Enterobacterales. Parsimony analysis and sequence comparisons revealed a large number of signal peptide gain and loss events, in which signal peptides emerge or disappear in the course of evolution. Signal peptide losses prevail over gains, an effect which is especially pronounced in the transition from the free-living or commensal to the endosymbiotic lifestyle. The disproportionate decline in the number of signal peptide-containing proteins in endosymbionts cannot be explained by the overall reduction of their genomes. Signal peptides can be gained and lost either by acquisition/elimination of the corresponding N-terminal regions or by gradual accumulation of mutations. The evolutionary dynamics of signal peptides in bacterial proteins represents a powerful mechanism of functional diversification.
同源蛋白在分泌能力方面是否存在差异？为了回答这个问题，我们研究了肠杆菌目中同源群中信号肽的分布。简约分析和序列比较揭示了大量的信号肽获得和丢失事件，其中信号肽在进化过程中出现或消失。信号肽的丢失超过了获得，这种效应在从自由生活或共生到内共生生活的转变中尤为明显。内共生体中含信号肽蛋白数量的不成比例下降不能用它们基因组的整体减少来解释。信号肽可以通过相应的 N 端区域的获得/消除或通过逐渐积累突变来获得和丢失。细菌蛋白中信号肽的进化动态代表了一种强大的功能多样化机制。
