Department of Microbiology, The Public Health Research Institute Center, UMDNJ, Newark NJ, USA.
BMC Microbiol. 2010 Feb 19;10:55. doi: 10.1186/1471-2180-10-55.
Bacteriophage Phi12 is a member of the Cystoviridae and is distinct from Phi6, the first member of that family. We have recently isolated a number of related phages and five showed high similarity to Phi12 in the amino acid sequences of several proteins. Bacteriophage Phi2954 is a member of this group.
Phi2954 was isolated from radish leaves and was found to have a genome of three segments of double-stranded RNA (dsRNA), placing it in the Cystoviridae. The base sequences for many of the genes and for the segment termini were similar but not identical to those of bacteriophage Phi12. However, the host specificity was for the type IV pili of Pseudomonas syringae HB10Y rather than for the rough LPS to which Phi12 attaches. Reverse genetics techniques enabled the production of infectious phage from cDNA copies of the genome. Phage were constructed with one, two or three genomic segments. Phage were also produced with altered transcriptional regulation. Although the pac sequences of Phi2954 show no similarity to those of Phi12, segment M of Phi2954 could be acquired by Phi12 resulting in a change of host specificity.
We have isolated a new member of the bacteriophage family Cystoviridae and find that although it shows similarity to other members of the family, it has unique properties that help to elucidate viral strategies for genomic packaging and gene expression.
噬菌 Phi12 是 Cystoviridae 家族的一员，与该家族的第一个成员 Phi6 不同。我们最近分离出了一些相关的噬菌体，其中有五个在几种蛋白质的氨基酸序列上与 Phi12 高度相似。噬菌 Phi2954 就是其中之一。
噬菌 Phi2954 是从萝卜叶片中分离出来的，其基因组由三个双链 RNA（dsRNA）片段组成，因此将其归类于 Cystoviridae 家族。许多基因和片段末端的碱基序列与噬菌 Phi12 相似但不完全相同。然而，其宿主特异性是针对丁香假单胞菌 HB10Y 的 IV 型菌毛，而不是 Phi12 附着的粗糙 LPS。反向遗传学技术使我们能够从基因组 cDNA 拷贝中生产出有感染性的噬菌体。噬菌可以用一个、两个或三个基因组片段构建。还可以通过改变转录调控来构建噬菌体。尽管 Phi2954 的 pac 序列与 Phi12 没有相似之处，但 Phi2954 的 M 片段可以被 Phi12 获得，从而改变宿主特异性。
我们已经分离到了一种新的 Cystoviridae 噬菌体家族成员，尽管它与该家族的其他成员具有相似性，但它具有独特的特性，有助于阐明病毒在基因组包装和基因表达方面的策略。
