Structural Changes in a Marine Podovirus Associated with Release of its Genome Into ProchlorococcusLiu, X., Zhang, Q., Murata, K., Baker, M.L., Sullivan, M.B., Fu, C., Dougherty, M., Schmid, M.F., Osburne, M.S., Chisholm, S.W., Chiu, W.
(2010) Nat Struct Mol Biol 17: 830
- PubMed: 20543830
- DOI: https://doi.org/10.1038/nsmb.1823
- Primary Citation of Related Structures:
- PubMed Abstract:
Podovirus P-SSP7 infects Prochlorococcus marinus, the most abundant oceanic photosynthetic microorganism. Single-particle cryo-electron microscopy yields icosahedral and asymmetrical structures of infectious P-SSP7 with 4.6-A and 9-A resolution, respectively. The asymmetric reconstruction reveals how symmetry mismatches are accommodated among five of the gene products at the portal vertex. Reconstructions of infectious and empty particles show a conformational change of the 'valve' density in the nozzle, an orientation difference in the tail fibers, a disordering of the C terminus of the portal protein and the disappearance of the core proteins. In addition, cryo-electron tomography of P-SSP7 infecting Prochlorococcus showed the same tail-fiber conformation as that in empty particles. Our observations suggest a mechanism whereby, upon binding to the host cell, the tail fibers induce a cascade of structural alterations of the portal vertex complex that triggers DNA release.
National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, Texas, USA.