分枝杆菌噬菌体Guo1环状基因组特征及生物学特性分析

Circular genetic information and biologic characteristics of mycobacteriophage Guo1

【目的】初步研究分枝杆菌噬菌体Guo1环状基因组特征及生物学特性。【方法】采用鸟枪法和重叠群组装策略完成Guo1全基因组测序;使用DNAStar、t RNAscan-SE、Promoter predictions、TRF、Glimmer、BLAST软件分别对噬菌体的一般基因组学特征、t RNA、启动子、串联重复序列和编码基因进行分析;运用BLAST软件检索与Guo1基因组相似的噬菌体并构建系统进化树,推断Guo1的分群;测定最佳感染复数、一步生长曲线以及对紫外线、氯仿、酒精、温度、p H的敏感性。【结果】噬菌体Guo1的基因组为全长40 086 nt的环状双链DNA,属于G群分枝杆菌噬菌体;含有59个推定基因,7个启动子序列和3个串联重复序列;Guo1对紫外线有较强抵抗性,对酒精、氯仿和高温敏感,最适温度为37°C,最适p H为7.0,最佳感染复数为0.01,潜伏期120 min,裂解期120 min,裂解量为47个。【结论】Guo1是首次发现的具有环状双链DNA结构的G群分枝杆菌噬菌体,完成了Guo1的全基因组测序,并初步分析了Guo1的基因组特征和生物学特性。

[Objective] To investigate the genetic and biologic characteristics of mycobacteriophage Guo1 with circular genome. [Methods] Sequenced the complete genome of Guo1 with Shot-gun library and config package strategy. Performed DNAStar, t RNAscan-SE, Promoter predictions, TRF, Glimmer, BLAST software for general genome characteristics, t RNA, promoter regions, tandem repeat sequences and putative function of predicted coding sequences, respectively. Utilized BLAST software to search for mycobacteriophages with genome similar as Guo1. Constructed phylogenetic tree to identify the cluster into which Guo1 should be grouped. Then measured the optimal multiplicity of infection and one-step growth curve, and observed the sensibility to ultraviolet, chloroform, alcohol, temperature, p H. [Results] Guo1 contains a double strand circular DNA with a full length of 40 086 nt, which belongs to the cluster G mycobacteriophage and which contains 59 putative genes, 7 promoter regions and three tandem repeat sequences. Guo1 is resistant to ultraviolet but sensitive to alcohol, chloroform and high temperature. The optimal temperature is 37 °C while the optimal p H is 7.0. The optimal MOI of Guo1 is about 0.01. One step growth of it showed that both latent period and burst period are 120 min, and the average burst size is about 47. [Conclusion] Guo1 is a cluster G mycobacteriophage with double strand circular DNA found for the first time. We sequenced the complete genome of Guo1 and identified the circular genetic information and biologic characteristics.