Abstract
We present here the first asymmetric, three-dimensional reconstruction of a tailed dsDNA virus, the mature bacteriophage φ{symbol}29, at subnanometer resolution. This structure reveals the rich detail of the asymmetric interactions and conformational dynamics of the φ{symbol}29 protein and DNA components, and provides novel insight into the mechanics of virus assembly. For example, the dodecameric head-tail connector protein undergoes significant rearrangement upon assembly into the virion. Specific interactions occur between the tightly packed dsDNA and the proteins of the head and tail. Of particular interest and novelty, an ∼60Å diameter toroid of dsDNA was observed in the connector-lower collar cavity. The extreme deformation that occurs over a small stretch of DNA is likely a consequence of the high pressure of the packaged genome. This toroid structure may help retain the DNA inside the capsid prior to its injection into the bacterial host.
Original language | English (US) |
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Pages (from-to) | 935-943 |
Number of pages | 9 |
Journal | Structure |
Volume | 16 |
Issue number | 6 |
DOIs | |
State | Published - Jun 11 2008 |
Bibliographical note
Funding Information:We thank Dr. Zeyun Yu for advice on the use of his volume segmentation program, the San Diego Supercomputer Center for access to TeraGrid computing, and Drs. Wei Xu, Witold Grochulski, and Michael Sherman for their help in initiating these ø29 cryoEM studies. This work was supported in part by the National Institutes of Health (grants GM-033050 to T.S.B. and DE-003606 to D.L.A. and S.G.), and NSF shared instrumentation grant BIR-9112921, support from the University of California-San Diego, and the Agouron Foundation (all to T.S.B.).
Keywords
- DNA
- MICROBIO
- PROTEINS