3w3c: Difference between revisions
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==Crystal structure of VirB core domain complexed with the cis-acting site upstream icsb promoter== | |||
<StructureSection load='3w3c' size='340' side='right'caption='[[3w3c]], [[Resolution|resolution]] 2.43Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3w3c]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Shigella_flexneri_2a Shigella flexneri 2a]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3W3C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3W3C 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]] 2.431Å</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=3w3c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3w3c OCA], [https://pdbe.org/3w3c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3w3c RCSB], [https://www.ebi.ac.uk/pdbsum/3w3c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3w3c ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/VIRB_SHIFL VIRB_SHIFL] Transcription activator for the invasion antigens IpaB, IpaC and IpaD. VirB is itself regulated by VirF. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
VirB activates transcription of virulence genes in Shigella flexneri by alleviating heat-stable nucleoid-structuring protein-mediated promoter repression. VirB is unrelated to the conventional transcriptional regulators, but homologous to the plasmid partitioning proteins. We determined the crystal structures of VirB HTH domain bound by the cis-acting site containing the inverted repeat, revealing that the VirB-DNA complex is related to ParB-ParS-like complexes, presenting an example that a ParB-like protein acts exclusively in transcriptional regulation. The HTH domain of VirB docks DNA major groove and provides multiple contacts to backbone and bases, in which the only specific base readout is mediated by R167. VirB only recognizes one half site of the inverted repeats containing the most matches to the consensus for VirB binding. The binding of VirB induces DNA conformational changes and introduces a bend at an invariant A-tract segment in the cis-acting site, suggesting a role of DNA remodeling. VirB exhibits positive cooperativity in DNA binding that is contributed by the C-terminal domain facilitating VirB oligomerization. The isolated HTH domain only confers partial DNA specificity. Additional determinants for sequence specificity may reside in N- or C-terminal domains. Collectively, our findings support and extend a previously proposed model for relieving heat-stable nucleoid-structuring protein-mediated repression by VirB. | |||
Structural insights into VirB-DNA complexes reveal mechanism of transcriptional activation of virulence genes.,Gao X, Zou T, Mu Z, Qin B, Yang J, Waltersperger S, Wang M, Cui S, Jin Q Nucleic Acids Res. 2013 Dec 1;41(22):10529-41. doi: 10.1093/nar/gkt748. Epub 2013, Aug 27. PMID:23985969<ref>PMID:23985969</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3w3c" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Transcriptional activator 3D structures|Transcriptional activator 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Shigella flexneri 2a]] | |||
[[Category: Cui S]] | |||
[[Category: Gao XP]] | |||
[[Category: Waltersperger S]] | |||
[[Category: Wang MT]] | |||
Latest revision as of 15:48, 8 November 2023
Crystal structure of VirB core domain complexed with the cis-acting site upstream icsb promoterCrystal structure of VirB core domain complexed with the cis-acting site upstream icsb promoter
Structural highlights
FunctionVIRB_SHIFL Transcription activator for the invasion antigens IpaB, IpaC and IpaD. VirB is itself regulated by VirF. Publication Abstract from PubMedVirB activates transcription of virulence genes in Shigella flexneri by alleviating heat-stable nucleoid-structuring protein-mediated promoter repression. VirB is unrelated to the conventional transcriptional regulators, but homologous to the plasmid partitioning proteins. We determined the crystal structures of VirB HTH domain bound by the cis-acting site containing the inverted repeat, revealing that the VirB-DNA complex is related to ParB-ParS-like complexes, presenting an example that a ParB-like protein acts exclusively in transcriptional regulation. The HTH domain of VirB docks DNA major groove and provides multiple contacts to backbone and bases, in which the only specific base readout is mediated by R167. VirB only recognizes one half site of the inverted repeats containing the most matches to the consensus for VirB binding. The binding of VirB induces DNA conformational changes and introduces a bend at an invariant A-tract segment in the cis-acting site, suggesting a role of DNA remodeling. VirB exhibits positive cooperativity in DNA binding that is contributed by the C-terminal domain facilitating VirB oligomerization. The isolated HTH domain only confers partial DNA specificity. Additional determinants for sequence specificity may reside in N- or C-terminal domains. Collectively, our findings support and extend a previously proposed model for relieving heat-stable nucleoid-structuring protein-mediated repression by VirB. Structural insights into VirB-DNA complexes reveal mechanism of transcriptional activation of virulence genes.,Gao X, Zou T, Mu Z, Qin B, Yang J, Waltersperger S, Wang M, Cui S, Jin Q Nucleic Acids Res. 2013 Dec 1;41(22):10529-41. doi: 10.1093/nar/gkt748. Epub 2013, Aug 27. PMID:23985969[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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