利普斯他汀高产菌株毒三素链霉菌AP617-N12CA的全基因组测序与分析

摘要：目的 解析利普斯他汀(lipstatin)高产菌株毒三素链霉菌AP617-N12CA (S. toxytricini AP617-N12CA)的基因组序列信息，为深入研究该菌株高产lipstatin的分子机理与调控机制奠定基础。方法 联合应用三代单分子测序技术和二代高通量测序技术对AP617-N12CA菌株进行全基因组测序，使用相关软件对测序数据进行进基因组组装、基因预测和功能注释，并对lipstatin及其他次级代谢产物生物合成基因簇进行分析预测。结果 AP617-N12CA菌株整个基因组大约6.99Mb，GC含量73.76%，含有6134个编码序列；基因组由一条长约6.38Mb的线型染色体和一个长约0.61Mb的线型质粒组成；同时预测得到22个次级代谢产物合成基因簇，其中lipstatin基因簇定位在线型质粒右臂区域而非在染色体上。结论 首次完成了AP617-N12CA菌株全基因组完成图绘制，在S. toxytricini菌中首次发现和描述了线型质粒，在线型质粒上定位并鉴定分析了lipstatin基因簇。为S. toxytricini的功能基因组学研究和lipstatin高产机理解析提供了基础数据，对后续相关研究具有重要意义。

Whole-genome sequencing and analysis of high producing strain Streptomyces toxytricini AP617-N12CA

Abstract Objective To analyze the genome sequence information of lipstatin high-producing strain S. toxytricini AP617-N12CA, and lay a foundation for further study on the mechanisms of high yield and regulation of lipstatin biosynthesis. Methods Based on single molecule real-time (SMRT) sequencing technology and Illumina HiSeq high-throughput sequencing technology, the whole genome of AP617-N12CA strain was sequenced. Then sequenced reads were assembled, the encoding genes were predicted, the biological functions of the differential genes were annotated, and the secondary metabolite synthetic gene clusters were predicted and analyzed with software. Results The genome size of AP617-N12CA was about 6.99 Mb with an overall G+C content of 73.76%, and 6,134 protein-coding genes were initially annotated. Remarkably, the genome of AP617-N12CA was composed of a single linear chromosome (6.38 Mb) and a single linear plasmid (0.61 Mb). Based on antiSMASH 2.0 analysis, 22 predicted secondary metabolite gene clusters were identified in AP617-N12CA, and the biosynthetic gene cluster for lipstatin was unexpectedly located on the right arm of the linear plasmid. Conclusion In this study, we firstly reported the complete genome sequence map of the strain AP617-N12CA, and firstly reported the presence of linear plasmid in thespecies of S. toxytricini. Unexpectedly, we found that the lipstatin biosynthetic gene cluster was located on the right arm of the linear plasmid. This study provided basic data for the analysis of the molecular mechanism of high-yield lipstatin in AP617-N12CA strain and subsequent functional genomics research of S.