View source for 5jj3


==Refined Structure of the Mature Virion Conformation of P22 Portal Protein==
<StructureSection load='5jj3' size='340' side='right'caption='[[5jj3]], [[Resolution|resolution]] 7.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5jj3]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_virus_P22 Salmonella virus P22]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5JJ3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5JJ3 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 7&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5jj3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5jj3 OCA], [https://pdbe.org/5jj3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5jj3 RCSB], [https://www.ebi.ac.uk/pdbsum/5jj3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5jj3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PORTL_BPP22 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.
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== Publication Abstract from PubMed ==
Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity for the packaging motor. Modelling studies indicate the structure of PC-portal is incompatible with DNA coaxially spooled around the portal vertex, suggesting that newly packaged DNA triggers the switch from PC- to MV-conformation. Thus, we propose the signal for termination of 'Headful Packaging' is a DNA-dependent symmetrization of portal protein.

Portal protein functions akin to a DNA-sensor that couples genome-packaging to icosahedral capsid maturation.,Lokareddy RK, Sankhala RS, Roy A, Afonine PV, Motwani T, Teschke CM, Parent KN, Cingolani G Nat Commun. 2017 Jan 30;8:14310. doi: 10.1038/ncomms14310. PMID:28134243<ref>PMID:28134243</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Portal protein 3D structures|Portal protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella virus P22]]
[[Category: Cingolani G]]
[[Category: Lokareddy RK]]
[[Category: Sankhala RS]]