Data from: Cryoelectron tomography of enveloped human cytomegalovirus particles

The compartmentalization of eukaryotic cells presents considerable
challenges to the herpesvirus life cycle. The herpesvirus tegument, a
bulky proteinaceous aggregate sandwiched between herpesviruses’ capsid and
envelope, is uniquely evolved to address these challenges, yet tegument
structure and organization remain poorly characterized. Here we use
deep-learning–enhanced cryoEM to investigate the tegument of human
cytomegalovirus virions and noninfectious enveloped particles (NIEPs; a
genome packaging-aborted state), revealing a portal-biased tegumentation
scheme. We resolve atomic structures of portal vertex-associated tegument
(PVAT) and identify multiple configurations of PVAT arising from layered
reorganization of pUL77, pUL48 (large tegument protein), and pUL47 (inner
tegument protein) assemblies. Analyses show pUL77 seals the last-packaged
viral genome end through electrostatic interactions, pUL77 and pUL48
harbor a head–linker–capsid-binding motif conducive to PVAT
reconfiguration, and pUL47/48 dimers form 45-nm–long filaments extending
from the portal vertex. These results provide a structural framework for
understanding how herpesvirus tegument facilitates and evolves during
processes spanning viral genome packaging to delivery.