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| | ==N-terminal dimerization domain of H-NS in complex with Hha (Salmonella Typhimurium)== | | ==N-terminal dimerization domain of H-NS in complex with Hha (Salmonella Typhimurium)== |
| - | <StructureSection load='4icg' size='340' side='right' caption='[[4icg]], [[Resolution|resolution]] 2.92Å' scene=''> | + | <StructureSection load='4icg' size='340' side='right'caption='[[4icg]], [[Resolution|resolution]] 2.92Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4icg]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Saltu Saltu]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ICG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ICG FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4icg]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium_str._LT2 Salmonella enterica subsp. enterica serovar Typhimurium str. LT2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ICG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ICG FirstGlance]. <br> |
| - | </td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">hns, hnsA, osmZ, STM1751, STMUK_1724 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=990282 SALTU]), hha, STM0473, STMUK_0480 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=990282 SALTU])</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=4icg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4icg OCA], [https://pdbe.org/4icg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4icg RCSB], [https://www.ebi.ac.uk/pdbsum/4icg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4icg ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4icg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4icg OCA], [http://pdbe.org/4icg PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4icg RCSB], [http://www.ebi.ac.uk/pdbsum/4icg PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/HNS_SALTY HNS_SALTY]] H-NS binds tightly to ds-DNA, increases its thermal stability and inhibits transcription. It also binds to ss-DNA and RNA but with a much lower affinity. H-NS has possible histone-like function. May be a global transcriptional regulator through its ability to bind to curved DNA sequences, which are found in regions upstream of a certain subset of promoters. It plays a role in the thermal control of pili production. It is subject to transcriptional auto-repression. It binds preferentially to the upstream region of its own gene recognizing two segments of DNA on both sides of a bend centered around -150 (By similarity). | + | [https://www.uniprot.org/uniprot/HNS_SALTY HNS_SALTY] H-NS binds tightly to ds-DNA, increases its thermal stability and inhibits transcription. It also binds to ss-DNA and RNA but with a much lower affinity. H-NS has possible histone-like function. May be a global transcriptional regulator through its ability to bind to curved DNA sequences, which are found in regions upstream of a certain subset of promoters. It plays a role in the thermal control of pili production. It is subject to transcriptional auto-repression. It binds preferentially to the upstream region of its own gene recognizing two segments of DNA on both sides of a bend centered around -150 (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Saltu]] | + | [[Category: Large Structures]] |
| - | [[Category: Ali, S S]] | + | [[Category: Salmonella enterica subsp. enterica serovar Typhimurium str. LT2]] |
| - | [[Category: Howell, P L]] | + | [[Category: Ali SS]] |
| - | [[Category: Navarre, W W]] | + | [[Category: Howell PL]] |
| - | [[Category: Robinson, H]] | + | [[Category: Navarre WW]] |
| - | [[Category: Stevenson, J]] | + | [[Category: Robinson H]] |
| - | [[Category: Whitney, J C]] | + | [[Category: Stevenson J]] |
| - | [[Category: Dna binding protein]]
| + | [[Category: Whitney JC]] |
| - | [[Category: Hha]]
| + | |
| Structural highlights
Function
HNS_SALTY H-NS binds tightly to ds-DNA, increases its thermal stability and inhibits transcription. It also binds to ss-DNA and RNA but with a much lower affinity. H-NS has possible histone-like function. May be a global transcriptional regulator through its ability to bind to curved DNA sequences, which are found in regions upstream of a certain subset of promoters. It plays a role in the thermal control of pili production. It is subject to transcriptional auto-repression. It binds preferentially to the upstream region of its own gene recognizing two segments of DNA on both sides of a bend centered around -150 (By similarity).
Publication Abstract from PubMed
The bacterial nucleoid associated proteins Hha and H-NS jointly repress horizontally acquired genes in Salmonella, including essential virulence loci encoded within Salmonella pathogenicity islands. Hha is known to interact with the N-terminal dimerization domain of H-NS, however the manner in which this interaction enhances transcriptional silencing is not understood. To further understand this process we solved the X-ray crystal structure of Hha in complex with the N-terminal dimerization domain of H-NS (H-NS1-46) to 3.2 A resolution. Two monomers of Hha bind to symmetrical sites on either side of the H-NS1-46 dimer. Disruption of the Hha/H-NS interaction by the H-NS site-specific mutation I11A, results in increased expression of the Hha/H-NS co-regulated gene hilA without affecting the expression levels of proV, a target gene repressed by H-NS in an Hha-independent fashion. Examination of the structure revealed a cluster of conserved basic amino acids that protrude from the surface of Hha on the opposite side of the Hha/H-NS1-46 interface. Hha mutants with a diminished positively charged surface maintain the ability to interact with H-NS but can no longer regulate hilA. Increased expression of the hilA locus did not correspond to significant depletion of H-NS at the promoter region in chromatin immunoprecipitation assays. However in vitro, we find Hha improves H-NS binding to target DNA fragments. Taken together, our results show for the first time how Hha and H-NS interact to direct transcriptional repression and reveal that a positively charged surface of Hha enhances the silencing activity of H-NS nucleoprotein filaments.
Structural Insights into the Regulation of Foreign Genes in Salmonella by the Hha/H-NS Complex.,Ali SS, Whitney JC, Stevenson J, Robinson H, Howell PL, Navarre WW J Biol Chem. 2013 Mar 20. PMID:23515315[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Ali SS, Whitney JC, Stevenson J, Robinson H, Howell PL, Navarre WW. Structural Insights into the Regulation of Foreign Genes in Salmonella by the Hha/H-NS Complex. J Biol Chem. 2013 Mar 20. PMID:23515315 doi:10.1074/jbc.M113.455378
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