Host RNA polymerase inhibitors encoded by φKMV-like phages of pseudomonas
Host RNA polymerase inhibitors encoded by φKMV-like phages of pseudomonas
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DOI：
10.1016/j.virol.2012.10.021
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发表时间：
2013-02-05
期刊：
影响因子：
3.7
通讯作者：
Severinov, Konstantin
中科院分区：
文献类型：
--
作者：
Klimuk, Evgeny;Akulenko, Natalia;Severinov, Konstantin
大肠杆菌噬菌体T7是编码单亚基RNA聚合酶（RNAP）的一个大型podovirus分支的创始成员。该家族的噬菌体依赖于宿主RNAP来转录早期病毒基因;病毒RNAP转录非早期病毒基因。T7及其近亲编码宿主RNAP的抑制剂，即gp 2蛋白。Gp 2是噬菌体发育所必需的，并确保宿主RNAP在感染后期不干扰病毒RNAP转录。在这里，我们确定了宿主RNAP抑制剂编码的一个子集的T7进化枝相关的phi KMV噬菌体的铜绿假单胞菌。我们证明，这些蛋白质是功能相同的T7 gp 2在体内和体外。一些假单胞菌噬菌体gp 2样蛋白抑制RNAP的能力由N-末端结构域调节，这在T7噬菌体同源物中是不存在的。这一发现表明，假单胞菌可能使用外部或内部的线索，以启动抑制宿主RNAP转录和gp 2样蛋白从这些假单胞菌可能是这些线索的受体。(C)2012 Elsevier Inc. All rights reserved.
Escherichia coli bacteriophage T7 is a founding member of a large clade of podoviruses encoding a single-subunit RNA polymerase (RNAP). Phages of the family rely on host RNAP for transcription of early viral genes; viral RNAP transcribes non-early viral genes. T7 and its close relatives encode an inhibitor of host RNAP, the gp2 protein. Gp2 is essential for phage development and ensures that host RNAP does not interfere with viral RNAP transcription at late stages of infection. Here, we identify host RNAP inhibitors encoded by a subset of T7 clade phages related to phi KMV phage of Pseudomonas aeruginosa. We demonstrate that these proteins are functionally identical to T7 gp2 in vivo and in vitro. The ability of some Pseudomonas phage gp2-like proteins to inhibit RNAP is modulated by N-terminal domains, which are absent from the T7 phage homolog. This finding indicates that Pseudomonas phages may use external or internal cues to initiate inhibition of host RNAP transcription and that gp2-like proteins from these phages may be receptors of these cues. (C) 2012 Elsevier Inc. All rights reserved.