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-Structure paper
Title | Structure of lactococcal phage p2 baseplate and its mechanism of activation. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 107, Issue 15, Page 6852-6857, Year 2010 |
Publish date | Apr 13, 2010 |
Authors | Giuliano Sciara / Cecilia Bebeacua / Patrick Bron / Denise Tremblay / Miguel Ortiz-Lombardia / Julie Lichière / Marin van Heel / Valérie Campanacci / Sylvain Moineau / Christian Cambillau / |
PubMed Abstract | Siphoviridae is the most abundant viral family on earth which infects bacteria as well as archaea. All known siphophages infecting gram+ Lactococcus lactis possess a baseplate at the tip of their ...Siphoviridae is the most abundant viral family on earth which infects bacteria as well as archaea. All known siphophages infecting gram+ Lactococcus lactis possess a baseplate at the tip of their tail involved in host recognition and attachment. Here, we report analysis of the p2 phage baseplate structure by X-ray crystallography and electron microscopy and propose a mechanism for the baseplate activation during attachment to the host cell. This approximately 1 MDa, Escherichia coli-expressed baseplate is composed of three protein species, including six trimers of the receptor-binding protein (RBP). RBPs host-recognition domains point upwards, towards the capsid, in agreement with the electron-microscopy map of the free virion. In the presence of Ca(2+), a cation mandatory for infection, the RBPs rotated 200 degrees downwards, presenting their binding sites to the host, and a channel opens at the bottom of the baseplate for DNA passage. These conformational changes reveal a novel siphophage activation and host-recognition mechanism leading ultimately to DNA ejection. |
External links | Proc Natl Acad Sci U S A / PubMed:20351260 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 2.6 - 26.0 Å |
Structure data | EMDB-1699: EMDB-1706: PDB-2wzp: PDB-2x53: PDB-4v5i: |
Chemicals | ChemComp-HOH: ChemComp-SR: ChemComp-CA: |
Source |
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Keywords | VIRAL PROTEIN / BASEPLATE / SIPHOVIRIDAE / LACTOCOCCUS LACTIS |