Identification of a tail assembly gene cluster from deep-sea thermophilic bacteriophage GVE2

In tailed dsDNA phages, the tail assembly gene cluster is of great importance for phage assembly and infection. Up to date, however, this concern is not addressed to thermophilic bacteriophages from deep-sea hydrothermal vents. In this investigation, a typically organized tail assembly gene cluster, encoding the tail protein, two phage-related proteins and tape measure protein, was revealed in the deep-sea thermophilic lytic phage GVE2 for the first time. As demonstrated by northern and western blots, the vp192 gene was expressed in the late stage of virus infection. The immuno-electron microscopy further indicated that the vp192-encoded polypeptide was the tail protein of GVE2. The results showed that a programmed translational frameshift existed in the tail assembly gene cluster of GVE2, suggesting the existence of a conserved tail assembly pathway in dsDNA tailed phages from deep sea. Our findings would be very helpful for understanding the assembly and infection of thermophilic bacteriophage in deep-sea hydrothermal vent.