植物乳杆菌编码复制起始蛋白天然质粒的系统进化分析

Phylogenetic analysis of natural plasmids encoding the replication initiation protein in Lactobacillus plantarum

【目的】探究复制起始蛋白(Replication initiation protein,Rep)是否可以作为天然质粒系统进化关系研究的分子标记。【方法】以植物乳杆菌天然质粒编码的Rep为研究对象,通过构建Rep系统进化树详细分析和讨论这些质粒的系统进化关系。【结果】植物乳杆菌45个编码Rep天然质粒可以划分为5个进化关系紧密的家族和1个独立进化质粒p G6302,家族1-4质粒可以进一步划分为10个进化关系更近的亚家族类群,因此这些质粒可能起源于6个祖先质粒。【结论】Rep氨基酸序列显示了适度的保守性和变异性,是植物乳杆菌编码Rep质粒进化研究理想的分子标记,为植物乳杆菌天然质粒系统进化研究提供了一种简单、有效的分析方法和标准,并为植物乳杆菌或其他乳酸菌天然质粒系统进化研究提供了分子水平的佐证和依据。

[Objective] In order to explore whether replication initiation protein （Rep） can be used as a molecular biomarker for the phylogenetic relationship study of natural plasmids. [Methods] The Reps of natural plasmids of Lactobacillus plantarum as a target, the phylogenetic relationships of these plasrnids were analyzed and discussed in detail by constructing Rep phylogenetic tree. [Results] A total of 45 plasmids encoding Rep in Lactobacillus plantarum could be clustered into 5 closely related families and 1 single plasmid pG6302, of which family 1 to 4 plasmids could be further subdivided into l0 subfamily groups with closer evolutionary relationships, suggesting that these plasmids may originate from the 6 ancestral plasmids. [Conclusion] Since the amino acid sequences of Reps show suitable conservation and variability, it may be an ideal molecular biomarker for phylogenetic relationship study of plasmids encoding Rep in Lactobacillus plantarum. The results could provide a simple and effective method and standard, as well as the evidence and basis at the molecular level for phylogenetic evolution study of natural plasmids encoding Rep in Lactobacillus plantarum or other lactic acid bacteria.