LAUSR

In this issue of the Protein & Cell Journal, a research team (from Institute of Biophysics, Chinese Academy of Sciences) led by professors Xiangxi Wang and Zihe Rao report the high-resolution structural and physical properties of the ATPdriven DNA packaging motor of the double-stranded (ds) herpesvirus (Yang et al. 2020). The structures of the portal vertex, the channel hub of the DNA packaging motor were also investigated, revealing essential protein-protein interactions in the assembly and maturation of herpesvirus procapsid (Chen et al. 2020; Wang et al. 2020). Their impressive data clearly demonstrated that the herpesvirus DNA packaging motor forms a hexameric structure and utilizes the revolving mechanism instead of rotation (Fig. 1). This is the first paper of its kind, with images in angstromscale resolution, to convincingly elucidate the structure data to end the 20-year debate on whether the structure or the viral DNA packaging motor is pentamer or hexamer, and whether the motion mechanism is rotation or revolution. An intriguing step during the assembly of dsDNA viruses is the translocation of their lengthy dsDNA genome into the preformed protein shells, called procapsids. This translocation event is driven by a biomotor. The herpesvirus DNA packaging motor is composed of three separate components: the ATPase pUL15 plus two regulator/fixer proteins puL28 and pUL33. Binding and hydrolysis of ATP by the complexes lead to conformational transition of the ATPase triggering DNA translocation. DNA translocation is also accompanied by the cleavage of the concatemeric DNA when the full-length of the herpesvirus genome is packaged. STRUCTURAL EVIDENCE OF THIS REPORT TO SUPPORT THE HEXAMER INSTEAD OF PENTAMER STRUCTURE