Development of Giant Bacteriophage φKZ Is Independent of the Host Transcription Apparatus
Development of Giant Bacteriophage φKZ Is Independent of the Host Transcription Apparatus
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DOI：
10.1128/jvi.01347-14
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发表时间：
2014-09-01
影响因子：
5.4
通讯作者：
Lavigne, Rob
中科院分区：
文献类型：
--
作者：
Ceyssens, Pieter-Jan;Minakhin, Leonid;Lavigne, Rob
铜绿假单胞菌噬菌体phi KZ是巨型噬菌体属的典型代表，其特征在于异常大的病毒粒子和基因组。通过将类似于280 kb phi KZ基因组的转录图谱解析到单核苷酸分辨率，我们将联合收割机369个phi KZ基因组合成134个操纵子。早期转录起始于分布在phi KZ基因组中并位于基因组同一链上的高度保守的富含AT的启动子。早期转录不需要噬菌体或宿主蛋白质合成。中晚期基因的转录依赖于蛋白质的合成，并由保守性较差的中晚期启动子介导。phi KZ的独特之处在于它能够在没有细菌RNA聚合酶（RNAP）酶活性的情况下完成其感染。我们提出，转录的phi KZ基因组是由两个phi KZ编码的，非经典的多亚基RNAP，其中之一是包装内的病毒粒子，另一个是早期基因的产物的连续行动。这种独特的，耐利福平的转录机制是保守的不同的巨型phage genus.IMPORTANCE-本文提出的数据提供，第一次，深入了解复杂的巨型噬菌体的转录计划。我们表明，铜绿假单胞菌巨大噬菌体phi KZ是能够感染和裂解其宿主细胞，并产生噬菌体后代的功能性细菌转录机制的情况下。这种独特的性质可以归因于两种噬菌体编码的推定RNAP酶，其含有细菌β和β '样RNAP亚基的非常远的同源物。
Pseudomonas aeruginosa bacteriophage phi KZ is the type representative of the giant phage genus, which is characterized by unusually large virions and genomes. By unraveling the transcriptional map of the similar to 280-kb phi KZ genome to single-nucleotide resolution, we combine 369 phi KZ genes into 134 operons. Early transcription is initiated from highly conserved AT-rich promoters distributed across the phi KZ genome and located on the same strand of the genome. Early transcription does not require phage or host protein synthesis. Transcription of middle and late genes is dependent on protein synthesis and mediated by poorly conserved middle and late promoters. Unique to phi KZ is its ability to complete its infection in the absence of bacterial RNA polymerase (RNAP) enzyme activity. We propose that transcription of the phi KZ genome is performed by the consecutive action of two phi KZ-encoded, noncanonical multisubunit RNAPs, one of which is packed within the virion, another being the product of early genes. This unique, rifampin-resistant transcriptional machinery is conserved within the diverse giant phage genus.IMPORTANCE The data presented in this paper offer, for the first time, insight into the complex transcriptional scheme of giant bacteriophages. We show that Pseudomonas aeruginosa giant phage phi KZ is able to infect and lyse its host cell and produce phage progeny in the absence of functional bacterial transcriptional machinery. This unique property can be attributed to two phage-encoded putative RNAP enzymes, which contain very distant homologues of bacterial beta and beta'-like RNAP subunits.