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==Nodavirus RNA replication protein A polymerase domain, local refinement==
<StructureSection load='8fmb' size='340' side='right'caption='[[8fmb]], [[Resolution|resolution]] 6.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8fmb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Flock_House_virus Flock House virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8FMB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8FMB FirstGlance]. <br>
</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=8fmb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8fmb OCA], [https://pdbe.org/8fmb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8fmb RCSB], [https://www.ebi.ac.uk/pdbsum/8fmb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8fmb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RDRP_FHV RDRP_FHV] RNA-dependent RNA polymerase which replicates the viral genome composed of 2 RNA segments, RNA1 and RNA2.
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== Publication Abstract from PubMed ==
Positive-strand RNA viruses replicate their genomes in virus-induced membrane vesicles, and the resulting RNA replication complexes are a major target for virus control. Nodavirus studies first revealed viral RNA replication proteins forming a 12-fold symmetric "crown" at the vesicle opening to the cytosol, an arrangement recently confirmed to extend to distantly related alphaviruses. Using cryoelectron microscopy (cryo-EM), we show that mature nodavirus crowns comprise two stacked 12-mer rings of multidomain viral RNA replication protein A. Each ring contains an ~19 nm circle of C-proximal polymerase domains, differentiated by strikingly diverged positions of N-proximal RNA capping/membrane binding domains. The lower ring is a "proto-crown" precursor that assembles prior to RNA template recruitment, RNA synthesis, and replication vesicle formation. In this proto-crown, the N-proximal segments interact to form a toroidal central floor, whose 3.1 A resolution structure reveals many mechanistic details of the RNA capping/membrane binding domains. In the upper ring, cryo-EM fitting indicates that the N-proximal domains extend radially outside the polymerases, forming separated, membrane-binding "legs." The polymerase and N-proximal domains are connected by a long linker accommodating the conformational switch between the two rings and possibly also polymerase movements associated with RNA synthesis and nonsymmetric electron density in the lower center of mature crowns. The results reveal remarkable viral protein multifunctionality, conformational flexibility, and evolutionary plasticity and insights into (+)RNA virus replication and control.

Nodavirus RNA replication crown architecture reveals proto-crown precursor and viral protein A conformational switching.,Zhan H, Unchwaniwala N, Rebolledo-Viveros A, Pennington J, Horswill M, Broadberry R, Myers J, den Boon JA, Grant T, Ahlquist P Proc Natl Acad Sci U S A. 2023 Jan 31;120(5):e2217412120. doi: , 10.1073/pnas.2217412120. Epub 2023 Jan 24. PMID:36693094<ref>PMID:36693094</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 8fmb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Flock House virus]]
[[Category: Large Structures]]
[[Category: Ahlquist P]]
[[Category: Broadberry R]]
[[Category: Grant T]]
[[Category: Horswill M]]
[[Category: Myers J]]
[[Category: Pennington J]]
[[Category: Rebolledo Viveros A]]
[[Category: Unchwaniwala N]]
[[Category: Zhan H]]
[[Category: Den Boon J]]