View source for 6g26


==The crystal structure of the Burkholderia pseudomallei HicAB complex==
<StructureSection load='6g26' size='340' side='right'caption='[[6g26]], [[Resolution|resolution]] 2.49&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6g26]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Burps Burps]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6G26 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6G26 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">BPSS0391 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=272560 BURPS]), BPSS0390 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=272560 BURPS])</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=6g26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6g26 OCA], [http://pdbe.org/6g26 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6g26 RCSB], [http://www.ebi.ac.uk/pdbsum/6g26 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6g26 ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Toxin-antitoxin (TA) systems are present in many bacteria and play important roles in bacterial growth, physiology, and pathogenicity. Those that are best studied are the type II TA systems, in which both toxins and antitoxins are proteins. The HicAB system is one of the prototypic TA systems, found in many bacterial species. Complex interactions between the protein toxin (HicA), the protein antitoxin (HicB), and the DNA upstream of the encoding genes regulate the activity of this system, but few structural details are available about how HicA destabilizes the HicB-DNA complex. Here, we determined the X-ray structures of HicB and the HicAB complex to 1.8 and 2.5 A resolution respectively and characterized their DNA interactions. This revealed that HicB forms a tetramer and HicA and HicB form a hetero-octameric complex that involves structural reorganization of the C-terminal (DNA-binding) region of HicB. Our observations indicated that HicA has a profound impact on binding of HicB to DNA sequences upstream of hicAB in a stoichiometric-dependent way. At low ratios of HicA:HicB, there was no effect on DNA binding, but at higher ratios, the affinity for DNA declined cooperatively, driving dissociation of the HicA:HicB:DNA complex.These results reveal the structural mechanisms by which HicA de-represses the HicB-DNA complex.

The molecular basis of protein toxin HicA-dependent binding of the protein antitoxin HicB to DNA.,Winter AJ, Williams C, Isupov MN, Crocker H, Gromova M, Marsh P, Wilkinson OJ, Dillingham MS, Harmer NJ, Titball RW, Crump MP J Biol Chem. 2018 Oct 18. pii: RA118.005173. doi: 10.1074/jbc.RA118.005173. PMID:30337369<ref>PMID:30337369</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Burps]]
[[Category: Large Structures]]
[[Category: Crump, M P]]
[[Category: Isupov, M N]]
[[Category: Williams, C]]
[[Category: Winter, A J]]
[[Category: Antitoxin]]
[[Category: N-terminal domain of the antitoxin hicb which acts as an inhibitor to hica]]