View source for 7jw1


==Satellite phage P4 procapsid including size determination (Sid) protein==
<SX load='7jw1' size='340' side='right' viewer='molstar' caption='[[7jw1]], [[Resolution|resolution]] 4.19&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7jw1]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Enterobacteria_phage_P4 Enterobacteria phage P4] and [https://en.wikipedia.org/wiki/Escherichia_virus_P2 Escherichia virus P2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7JW1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7JW1 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4.19&#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=7jw1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7jw1 OCA], [https://pdbe.org/7jw1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7jw1 RCSB], [https://www.ebi.ac.uk/pdbsum/7jw1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7jw1 ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/VSID_BPP4 VSID_BPP4] Although P4 acquires its capsid proteins from helper phages such as P2, it possesses the ability to assemble capsids that are only one-third the size of the helper's capsid. The sid protein is responsible for the assembly of P4-sized shells. It forms a P4-specific scaffold with icosahedral symmetry on the outside of the procapsid-like particles.<ref>PMID:7643390</ref> 
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== Publication Abstract from PubMed ==
P4 is a mobile genetic element (MGE) that can exist as a plasmid or integrated into its Escherichia coli host genome, but becomes packaged into phage particles by a helper bacteriophage, such as P2. P4 is the original example of what we have termed "molecular piracy", the process by which one MGE usurps the life cycle of another for its own propagation. The P2 helper provides most of the structural gene products for assembly of the P4 virion. However, when P4 is mobilized by P2, the resulting capsids are smaller than those normally formed by P2 alone. The P4-encoded protein responsible for this size change is called Sid, which forms an external scaffolding cage around the P4 procapsids. We have determined the high-resolution structure of P4 procapsids, allowing us to build an atomic model for Sid as well as the gpN capsid protein. Sixty copies of Sid form an intertwined dodecahedral cage around the T = 4 procapsid, making contact with only one out of the four symmetrically non-equivalent copies of gpN. Our structure provides a basis for understanding the sir mutants in gpN that prevent small capsid formation, as well as the nms "super-sid" mutations that counteract the effect of the sir mutations, and suggests a model for capsid size redirection by Sid.

Structure of the Capsid Size-Determining Scaffold of "Satellite" Bacteriophage P4.,Kizziah JL, Rodenburg CM, Dokland T Viruses. 2020 Aug 27;12(9). pii: v12090953. doi: 10.3390/v12090953. PMID:32867300<ref>PMID:32867300</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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[[Category: Enterobacteria phage P4]]
[[Category: Escherichia virus P2]]
[[Category: Large Structures]]
[[Category: Dokland T]]
[[Category: Kizziah JL]]