链霉菌中一类同源非典型端粒的克隆及分析  

Cloning and analysis of a class of homologous atypical telomeres of Streptomyces

作　　者：李鹏 刘兰[1] 王通 黄筱萍[1] LI Peng;LIU Lan;WANGTong;HUANG Xiaoping(Institute of Microbiology,Jiangxi Academy of Sciences,Nanchang,Jiangxi 330095,China)

机构地区：[1]江西省科学院微生物研究所,江西南昌330095

出　　处：《湖南农业大学学报（自然科学版）》2024年第4期42-50,共9页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：国家自然科学基金项目(31900061);江西省科学院科研开发专项基金项目(2017-YYB-03)。

摘　　要：采用自连接-PCR的方法克隆和测序了Streptomyces cattleya DSM46488、Streptomyces mobaraensisDSM40847及Streptomyces davawensisJCM4913的端粒,序列比对发现,这3种端粒具有较高的序列相似性,前60个核苷酸的序列相似性达到了80%以上;在二级结构水平,这些端粒含有多个回文序列,其中,包含相同的回文序列I和II,但并不能通过折返形成超级发夹结构;Streptomyces cattleya DSM46488、StreptomycesmobaraensisDSM40847及Streptomyces davawensis JCM4913的端粒与线性质粒pSHJG1端粒及Streptomyces albus J1074染色体端粒均具有较高的序列相似性;系统发育分析显示它们与典型端粒及其他非典型端粒处于不同的进化分支,S.cattleyaDSM46488、S.mobaraensis DSM40847、S.davawensisJCM4913、S.albus J1074及S.hydroscopicussubsp.Jinggangensis 5008都编码同源的潜在末端蛋白-端粒相关蛋白,暗示了这类同源的非典型端粒系统广泛存在于链霉菌中。In this study,the telomeres of StreptomycescattleyaDSM46488,S.mobaraensisDSM40847 andS.davawensisJCM4913 were cloned and sequenced by using self-ligation-PCR method.High sequence similarity,especially within the first 60 nucleotides(identity>80%),was revealed by the sequence alignment.At the secondary structural level,these telomeres containedmultiple palindromic sequences,including the same palindromic sequences I and II.However,super-hairpin structure could not be formed by folding back of palindrome I with the internal palindromes.Moreover,the three new telomeres cloned from S.cattleyaDSM46488,S.mobaraensisDSM40847 and S.davawensisJCM4913 showed sequence similarity to telomeres of linear plasmid pSHJG1 and S.albusJ1074 chromosome.Phylogenetic analysis based on the first 100 nucleotides of telomeres demonstrated that they were in different phylogenetic branches from the typical telomeres and other atypical telomeres.In addition,these strains encoded the homologous putative terminal proteins-telomere associated proteins,indicating that the class of homologous atypical telomere system was widely distributed within Streptomyces.

关 键 词：链霉菌 线性复制子 同源非典型端粒 端粒系统 回文序列 末端蛋白-端粒相关蛋白 

分 类 号：Q934.3[生物学—微生物学]