Structure of bacteriophage SPP1 head-to-tail connection reveals mechanism for viral DNA gating
Lhuillier, S. and Gallopin, M. and Gilquin, B. and Brasiles, S. and Lancelot, N. and Letellier, G. and Gilles, M. and Dethan, G. and Orlova, Elena and Couprie, J. and Tavares, P. and Zinn-Justin, S. (2009) Structure of bacteriophage SPP1 head-to-tail connection reveals mechanism for viral DNA gating. Proceedings of the National Academy of Sciences of the United States of America 106 (21), pp. 8507-8512. ISSN 0027-8424.
In many bacterial viruses and in certain animal viruses, the double-stranded DNA genome enters and exits the capsid through a portal gatekeeper. We report a pseudoatomic structure of a complete portal system. The bacteriophage SPP1 gatekeeper is composed of dodecamers of the portal protein gp6, the adaptor gp15, and the stopper gp16. The solution structures of gp15 and gp16 were determined by NMR. They were then docked together with the X-ray structure of gp6 into the electron density of the ≈1-MDa SPP1 portal complex purified from DNA-filled capsids. The resulting structure reveals that gatekeeper assembly is accompanied by a large rearrangement of the gp15 structure and by folding of a flexible loop of gp16 to form an intersubunit parallel β-sheet that closes the portal channel. This stopper system prevents release of packaged DNA. Disulfide cross-linking between β-strands of the stopper blocks the key conformational changes that control genome ejection from the virus at the beginning of host infection.
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Research Centre:||Structural Molecular Biology, Institute of (ISMB)|
|Date Deposited:||04 Aug 2010 14:09|
|Last Modified:||06 Dec 2016 11:14|
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