【摘要】 采用自连接–PCR的方法克隆和测序了StreptomycescattleyaDSM46488、Streptomycesmobaraensis DSM40847及Streptomyces davawensis JCM4913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、Streptomyces mobaraensis DSM40847及StreptomycesdavawensisJCM4913的端粒与线性质粒pSHJG1端粒及StreptomycesalbusJ1074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. cattleya DSM46488、S. mobaraensis DSM40847、S. davawensis JCM4913、S. albus J1074及S. hydroscopicus subsp.Jinggangensis5008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。更多还原

【Abstract】 In this study, the telomeres of Streptomyces cattleya DSM46488, S. mobaraensis DSM40847 and S.davawensis JCM4913 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 contained multiple 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. cattleya DSM46488, S. mobaraensis DSM40847 and S.davawensis JCM4913 showed sequence similarity to telomeres of linear plasmid pSHJG1 and S. albus J1074chromosome. 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.更多还原