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4v4k

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Bacteriophage P22 Portal Protein bound to middle Tail Factor GP4. This file contain the second biological assembly

Structural highlights

4v4k is a 48 chain structure with sequence from Salmonella virus P22. This structure supersedes the now removed PDB entries 1vt0 and 3lj4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.251Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PORTL_BPP22 Required for successful condensation of DNA within the capsid. Gp1 is a minor structural protein. The portal protein is present as a single ring-shaped dodecamer located at the point where tails attach. It is through this ring that DNA is thought to enter the prohead.

Publication Abstract from PubMed

DNA viruses such as bacteriophages and herpesviruses deliver their genome into and out of the capsid through large proteinaceous assemblies, known as portal proteins. Here, we report two snapshots of the dodecameric portal protein of bacteriophage P22. The 3.25-A-resolution structure of the portal-protein core bound to 12 copies of gene product 4 (gp4) reveals a ~1.1-MDa assembly formed by 24 proteins. Unexpectedly, a lower-resolution structure of the full-length portal protein unveils the unique topology of the C-terminal domain, which forms a ~200-A-long alpha-helical barrel. This domain inserts deeply into the virion and is highly conserved in the Podoviridae family. We propose that the barrel domain facilitates genome spooling onto the interior surface of the capsid during genome packaging and, in analogy to a rifle barrel, increases the accuracy of genome ejection into the host cell.

Three-dimensional structure of a viral genome-delivery portal vertex.,Olia AS, Prevelige PE Jr, Johnson JE, Cingolani G Nat Struct Mol Biol. 2011 May;18(5):597-603. Epub 2011 Apr 17. PMID:21499245^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Olia AS, Prevelige PE Jr, Johnson JE, Cingolani G. Three-dimensional structure of a viral genome-delivery portal vertex. Nat Struct Mol Biol. 2011 May;18(5):597-603. Epub 2011 Apr 17. PMID:21499245 doi:10.1038/nsmb.2023