Attai Hedieh, Boon Maarten, Phillips Kenya, Noben Jean-Paul, Lavigne Rob, Brown Pamela J B
Division of Biological Sciences, University of Missouri, Columbia, MO, United States.
Laboratory of Gene Technology, KU Leuven, Leuven, Belgium.
Front Microbiol. 2018 Aug 14;9:1861. doi: 10.3389/fmicb.2018.01861. eCollection 2018.
is a plant pathogen that causes crown gall disease, leading to the damage of agriculturally-important crops. As part of an effort to discover new phages that can potentially be used as biocontrol agents to prevent crown gall disease, we isolated and characterized phage Atu_ph07 from Sawyer Creek in Springfield, MO, using the virulent strain C58 as a host. After surveying its host range, we found that Atu_ph07 exclusively infects . Time-lapse microscopy of cells subjected to infection at a multiplicity of infection (MOI) of 10 with Atu_ph07 reveals that lysis occurs within 3 h. Transmission electron microscopy (TEM) of virions shows that Atu_ph07 has a typical morphology with an icosahedral head, long tail, and tail fibers. The sequenced genome of Atu_ph07 is 490 kbp, defining it as a jumbo phage. The Atu_ph07 genome contains 714 open reading frames (ORFs), including 390 ORFs with no discernable homologs in other lineages (ORFans), 214 predicted conserved hypothetical proteins with no assigned function, and 110 predicted proteins with a functional annotation based on similarity to conserved proteins. The proteins with predicted functional annotations share sequence similarity with proteins from bacteriophages and bacteria. The functionally annotated genes are predicted to encode DNA replication proteins, structural proteins, lysis proteins, proteins involved in nucleotide metabolism, and tRNAs. Characterization of the gene products reveals that Atu_ph07 encodes homologs of 16 T4 core proteins and is closely related to Rak2-like phages. Using ESI-MS/MS, the majority of predicted structural proteins could be experimentally confirmed and 112 additional virion-associated proteins were identified. The genomic characterization of Atu_ph07 suggests that this phage is lytic and the dynamics of Atu_ph07 interaction with its host indicate that this phage may be suitable for inclusion in a phage cocktail to be used as a biocontrol agent.
是一种植物病原体，可导致冠瘿病，从而损害重要的农作物。作为发现可潜在用作生物防治剂以预防冠瘿病的新型噬菌体的工作的一部分，我们以强毒株C58作为宿主，从密苏里州斯普林菲尔德的索耶溪中分离并鉴定了噬菌体Atu_ph07。在调查其宿主范围后，我们发现Atu_ph07仅感染 。用Atu_ph07以感染复数（MOI）为10对 细胞进行感染的延时显微镜观察显示，裂解在3小时内发生。病毒粒子的透射电子显微镜（TEM）显示，Atu_ph07具有典型的 形态，有二十面体头部、长尾和尾丝。Atu_ph07的测序基因组为490 kbp，将其定义为巨型噬菌体。Atu_ph07基因组包含714个开放阅读框（ORF），其中包括390个在其他谱系中无明显同源物的ORF（孤儿基因）、214个预测的保守假设蛋白（无指定功能）以及110个基于与保守蛋白相似性而具有功能注释的预测蛋白。具有预测功能注释的蛋白与来自噬菌体和细菌的蛋白具有序列相似性。功能注释基因预计编码DNA复制蛋白、结构蛋白、裂解蛋白、参与核苷酸代谢的蛋白和tRNA。基因产物的表征表明，Atu_ph07编码16种T4核心蛋白的同源物，并且与Rak2样噬菌体密切相关。使用电喷雾串联质谱（ESI-MS/MS），大多数预测的结构蛋白可以通过实验得到证实，并且还鉴定出了112种额外的病毒粒子相关蛋白。Atu_ph07的基因组特征表明该噬菌体具有裂解性，并且Atu_ph07与其宿主相互作用的动力学表明该噬菌体可能适合包含在用作生物防治剂的噬菌体混合物中。
