Characterization of the relationship between integrase, excisionase and antirepressor activities associated with a superinfecting Shiga toxin encoding bacteriophage.
Characterization of the relationship between integrase, excisionase and antirepressor activities associated with a superinfecting Shiga toxin encoding bacteriophage.
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DOI：
10.1093/nar/gkq923
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发表时间：
2011-03
影响因子：
14.9
通讯作者：
Allison HE
中科院分区：
文献类型：
--
作者：
Fogg PC;Rigden DJ;Saunders JR;McCarthy AJ;Allison HE
产志贺毒素大肠杆菌在20世纪80年代初作为一种新的食源性病原体出现，主要是由编码志贺毒素的Lambdoid噬菌体的扩散推动的。至少其中一些STX噬菌体表现出与Lambda噬菌体本身显著不同的重叠感染表型，通过原位重组进一步推动噬菌体进化，增加宿主范围，并潜在地增加宿主的致病谱。在这里，STX噬菌体Φ24B整合酶在多种溶原菌培养中的表达水平增加，而同源CI抑制物对整合酶表达的抑制显然可以忽略不计。发现Φ24B内转录起始区和启动子区域与计算机预测的结果不同。该整合酶的单向活性是在原位可诱导的三组分反应中测定的。这表明Φ24B必须编码一个新的方向性因子，该因子在原噬菌体诱导过程中控制切除事件。随后，通过互补实验对该酶进行了鉴定和鉴定。此外，对先前关于CI失活导致对重叠感染缺乏免疫力的假设进行了重新讨论，并提出了一个新的假说，涉及该蛋白在促进Φ24B原噬菌体有效诱导中的作用。
Shigatoxigenic Escherichia coli emerged as new food borne pathogens in the early 1980s, primarily driven by the dispersal of Shiga toxin-encoding lambdoid bacteriophages. At least some of these Stx phages display superinfection phenotypes, which differ significantly from lambda phage itself, driving through in situ recombination further phage evolution, increasing host range and potentially increasing the host's pathogenic profile. Here, increasing levels of Stx phage Φ24B integrase expression in multiple lysogen cultures are demonstrated along with apparently negligible repression of integrase expression by the cognate CI repressor. The Φ24B int transcription start site and promoter region were identified and found to differ from in silico predictions. The unidirectional activity of this integrase was determined in an in situ, inducible tri-partite reaction. This indicated that Φ24B must encode a novel directionality factor that is controlling excision events during prophage induction. This excisionase was subsequently identified and characterized through complementation experiments. In addition, the previous proposal that a putative antirepressor was responsible for the lack of immunity to superinfection through inactivation of CI has been revisited and a new hypothesis involving the role of this protein in promoting efficient induction of the Φ24B prophage is proposed.
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影响因子：
14.9
作者：
Bhardwaj N;Langlois RE;Zhao G;Lu H
通讯作者：
Lu H
影响因子：
3.6
作者：
AKASHI, S;JOH, K;NAKAMURA, T
通讯作者：
NAKAMURA, T
DOI：
10.1111/j.1749-6632.1980.tb27987.x
发表时间：
1980-01-01
影响因子：
5.2
作者：
Botstein, D
通讯作者：
Botstein, D
DOI：
10.1073/pnas.0607820104
发表时间：
2007-02-13
影响因子：
11.1
作者：
Abbani, Mohamad A.;Papagiannis, Christie V.;Clubb, Robert T.
通讯作者：
Clubb, Robert T.
影响因子：
5.6
作者：
Ahmad, S;Sarai, A
通讯作者：
Sarai, A