Download MendeleyIn situ structures of the portal-neck-tail complex of bacteriophage T4 inform a viral genome positioning mechanism.
Fokine, A., Zhu, J., Klose, T., Vago, F., Arnaud, C.A., Wang, Z., Khare, B., Rossmann, M.G., Chen, Z., Sun, L., Fang, Q., Kuhn, R.J., Rao, V.B.(2026) Nat Commun 17
- PubMed: 41720772 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1038/s41467-026-69106-8
- Primary Citation Related Structures:
9MKB - PubMed Abstract:
The post-genome packaging mechanisms that govern the assembly of an infectious virion are poorly understood in bacteriophages and other viruses. Here, our near-atomic resolution cryo-EM structural analyses uncovered an assembly- and conformation-driven genome positioning mechanism in the tailed bacteriophage T4. We show that following headful packaging, which generates a pressurized head, a global conformational change occurs in the portal structure, probably triggering packaging termination and ejection of the packaging motor. Our high-resolution structures of the neck of the virion further show that the neck undergoes conformational changes upon docking of a pre-assembled tail onto the sealed neck, which then opens a genome-gate. Driven by the pressure of the packaged DNA, the genome travels through open neck channels, binds and compresses the resident tape-measure protein, and halts at the bottom of the second topmost disk of the tail tube. Pressure-suspended within the virion's innermost tunnel and secured by a baseplate plug, the genome remains poised to flow through the tunnel into a host cell upon receiving the host receptor recognition signal.
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA. afokine@purdue.edu.
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