Structural basis for genome packaging, retention, and ejection in human cytomegalovirus.
Nat Commun
; 12(1): 4538, 2021 07 27.
Article
em En
| MEDLINE
| ID: mdl-34315863
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Genoma Viral
/
Citomegalovirus
/
Empacotamento do DNA
Limite:
Humans
Idioma:
En
Revista:
Nat Commun
Assunto da revista:
BIOLOGIA
/
CIENCIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
China