Satellite phage TLCφ enables toxigenic conversion by CTX phage through dif site alteration.
Satellite phage TLCφ enables toxigenic conversion by CTX phage through dif site alteration.
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细菌染色体通常携带整合的遗传元件（例如，质粒、转座子、原噬菌体和岛），其精确功能和对宿主细菌进化适应性的贡献是未知的。霍乱弧菌中编码霍乱毒素的CTX前噬菌体与一个功能未知的染色体整合元件（称为毒素连锁隐蔽元件（TLC））相邻。在这里，我们报告表征的TLC相关元件，对应于卫星丝状噬菌体（TLC-Kn 1）的基因组，它使用另一个丝状噬菌体（fs 2）的形态发生基因，形成感染性TLC-Kn 1噬菌体颗粒。TLC-Kn B11噬菌体基因组携带与dif重组序列相似的序列，其在使用XerC和XerD重组酶的染色体二聚体解析中起作用。dif序列也被溶原性丝状真菌（例如，CTX-10）用于其基因组的染色体整合。二聚体分解缺陷的细菌细胞通常表现出异常的丝状细胞形态。我们发现TLC-Kn B1基因组的获得和染色体整合恢复了霍乱弧菌野生型和突变株的完美差异位点和正常形态，这些突变株显示出差异表型。此外，具有TLC-Kn β 1的非致突变性霍乱弧菌的溶原性通过将CTX β整合到恢复的dif位点中促进其随后的致突变性转化。这些结果揭示了一个显着水平的合作之间的相互作用的多个丝状菌的出现，导致霍乱的细菌病原体。
Bacterial chromosomes often carry integrated genetic elements (e.g., plasmids, transposons, prophages, and islands) whose precise function and contribution to the evolutionary fitness of the host bacterium are unknown. The CTXϕ prophage, which encodes cholera toxin in Vibrio cholerae, is known to be adjacent to a chromosomally integrated element of unknown function termed the toxin-linked cryptic (TLC). Here we report characterization of a TLC-related element that corresponds to the genome of a satellite filamentous phage (TLC-Knϕ1) which uses the morphogenesis genes of another filamentous phage (fs2ϕ) to form infectious TLC-Knϕ1 phage particles. The TLC-Knϕ1 phage genome carries a sequence similar to the dif recombination sequence which functions in chromosome dimer resolution using XerC and XerD recombinases. The dif sequence is also exploited by lysogenic filamentous phages (e.g., CTXϕ) for chromosomal integration of their genomes. Bacterial cells defective in the dimer resolution often show an aberrant filamentous cell morphology. We found that acquisition and chromosomal integration of the TLC-Knϕ1 genome restored a perfect dif site and normal morphology to V. cholerae wild type and mutant strains that displayed dif- filamentation phenotypes. Furthermore, lysogeny of a dif- nontoxigenic V. cholerae with TLC-Knϕ1 promoted its subsequent toxigenic conversion through integration of CTXϕ into the restored dif site. These results reveal a remarkable level of cooperative interactions between multiple filamentous phages in the emergence of the bacterial pathogen that causes cholera.
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DOI：
10.1073/pnas.0803281105
发表时间：
2008-06-24
影响因子：
11.1
作者：
Cameron, D. Ewen;Urbach, Jonathan M.;Mekalanos, John J.
通讯作者：
Mekalanos, John J.
影响因子：
3.6
作者：
Rubin, EJ;Lin, W;Waldor, MK
通讯作者：
Waldor, MK
影响因子：
4.8
作者：
Kimsey, HH;Waldor, MK
通讯作者：
Waldor, MK
影响因子：
2.8
作者：
Ikema, M;Honma, Y
通讯作者：
Honma, Y
影响因子：
3.2
作者：
Iida, T;Makino, K;Honda, T
通讯作者：
Honda, T