Researchers Reveal Structure of Poxvirus Portal Complex That Controls Molecular Exchange
Scientists used cryo-electron tomography to determine the atomic structure of a portal complex embedded in poxvirus cores, resolving it at 7.1 and 4.9 angstrom resolution. The portal is made of three viral proteins (E8, E6, and L3) and functions as a selective gate allowing RNA and small molecules to pass while blocking double-stranded DNA and immune sensors. This structural discovery provides insights into how poxviruses replicate and identifies potential targets for antiviral drugs.
Researchers have determined the three-dimensional structure of a portal complex that sits on the surface of poxvirus cores, using advanced cryo-electron tomography techniques. The portal is assembled from three viral proteins—E8, E6, and L3—and the team constructed an atomic model of the pore structure at high resolution. The analysis reveals that the pore is selectively permeable: it allows RNA and smaller negatively charged molecules to pass through while geometrically and electrostatically excluding double-stranded DNA and cytosolic DNA sensors that would trigger host immune responses. This selective permeability is critical to poxvirus replication, as the viral core serves as a compartment for early gene transcription in the host cytoplasm. The findings establish a structural framework for understanding how poxviruses manage molecular exchange with their host and identify the portal complex as a potential target for developing antiviral interventions.
What's missing
The study does not discuss potential limitations of the cryo-electron tomography approach, such as resolution artifacts or the extent to which the static structures captured represent the dynamic behavior of the portal during active viral replication. Additionally, the paper does not specify which poxvirus species was studied or whether the portal architecture is conserved across different poxviruses.
What different sources said
- bioRxivCenter
Architecture of a portal complex embedded in the poxvirus core
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