7ETM

C6 portal vertex in the enveloped virion capsid

Summary for 7ETM

• Entry DOI: 10.2210/pdb7etm/pdb
• EMDB information: 31299
• Descriptor: Portal protein (1 entity in total)
• Functional Keywords: c6 portal vertex, enveloped capsid, viral protein
• Biological source: Human cytomegalovirus (HHV-5, Human herpesvirus 5)
• Total number of polymer chains: 12
• Total formula weight: 943617.66

Authors

Li, Z.,Yu, X. (deposition date: 2021-05-13, release date: 2021-07-14, Last modification date: 2025-07-02)

Primary citation

Li, Z.,Pang, J.,Dong, L.,Yu, X.
Structural basis for genome packaging, retention, and ejection in human cytomegalovirus.
Nat Commun, 12:4538-4538, 2021

PubMed Abstract: How the human cytomegalovirus (HCMV) genome-the largest among human herpesviruses-is packaged, retained, and ejected remains unclear. We present the in situ structures of the symmetry-mismatched portal and the capsid vertex-specific components (CVSCs) of HCMV. The 5-fold symmetric 10-helix anchor-uncommon among known portals-contacts the portal-encircling DNA, which is presumed to squeeze the portal as the genome packaging proceeds. We surmise that the 10-helix anchor dampens this action to delay the portal reaching a "head-full" packaging state, thus facilitating the large genome to be packaged. The 6-fold symmetric turret, latched via a coiled coil to a helix from a major capsid protein, supports the portal to retain the packaged genome. CVSCs at the penton vertices-presumed to increase inner capsid pressure-display a low stoichiometry, which would aid genome retention. We also demonstrate that the portal and capsid undergo conformational changes to facilitate genome ejection after viral cell entry.

PubMed: 34315863
DOI: 10.1038/s41467-021-24820-3

Experimental method

ELECTRON MICROSCOPY (5.9 Å)