View source for 4zc3


==DNA binding domain of small terminase SF6 phage==
<StructureSection load='4zc3' size='340' side='right'caption='[[4zc3]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4zc3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_phage_SF6 Bacillus phage SF6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZC3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZC3 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]] 1.4&#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=4zc3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zc3 OCA], [https://pdbe.org/4zc3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zc3 RCSB], [https://www.ebi.ac.uk/pdbsum/4zc3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zc3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TERS_BPSF6 TERS_BPSF6] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The helix-turn-helix (HTH) motif features frequently in protein DNA-binding assemblies. Viral pac site-targeting small terminase proteins possess an unusual architecture in which the HTH motifs are displayed in a ring, distinct from the classical HTH dimer. Here we investigate how such a circular array of HTH motifs enables specific recognition of the viral genome for initiation of DNA packaging during virus assembly. We found, by surface plasmon resonance and analytical ultracentrifugation, that individual HTH motifs of the Bacillus phage SF6 small terminase bind the packaging regions of SF6 and related SPP1 genome weakly, with little local sequence specificity. Nuclear magnetic resonance chemical shift perturbation studies with an arbitrary single-site substrate suggest that the HTH motif contacts DNA similarly to how certain HTH proteins contact DNA non-specifically. Our observations support a model where specificity is generated through conformational selection of an intrinsically bent DNA segment by a ring of HTHs which bind weakly but cooperatively. Such a system would enable viral gene regulation and control of the viral life cycle, with a minimal genome, conferring a major evolutionary advantage for SPP1-like viruses.

DNA recognition for virus assembly through multiple sequence-independent interactions with a helix-turn-helix motif.,Greive SJ, Fung HK, Chechik M, Jenkins HT, Weitzel SE, Aguiar PM, Brentnall AS, Glousieau M, Gladyshev GV, Potts JR, Antson AA Nucleic Acids Res. 2015 Dec 15. pii: gkv1467. PMID:26673721<ref>PMID:26673721</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4zc3" style="background-color:#fffaf0;"></div>

==See Also==
*[[Terminase 3D Structures|Terminase 3D Structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Bacillus phage SF6]]
[[Category: Large Structures]]
[[Category: Antson AA]]
[[Category: Chechik M]]
[[Category: Greive SJ]]
[[Category: Jenkins HT]]