View source for 5jaa


==Crystal structure of the HigBA2 toxin-antitoxin complex==
<StructureSection load='5jaa' size='340' side='right'caption='[[5jaa]], [[Resolution|resolution]] 2.99&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5jaa]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae_O1_biovar_El_Tor_str._N16961 Vibrio cholerae O1 biovar El Tor str. N16961]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5JAA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5JAA 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]] 2.993&#8491;</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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5jaa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5jaa OCA], [https://pdbe.org/5jaa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5jaa RCSB], [https://www.ebi.ac.uk/pdbsum/5jaa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5jaa ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HIGA2_VIBCH HIGA2_VIBCH] Antitoxin component of a toxin-antitoxin (TA) module that counteracts the effect of the HigB-2 toxin. Binds to its own promoter and regulates transcription of the higB-2/higA-2 operon.<ref>PMID:17020579</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Toxin-antitoxin (TA) modules are small operons involved in bacterial stress response and persistence. higBA operons form a family of TA modules with an inverted gene organization and a toxin belonging to the RelE/ParE superfamily. Here, we present the crystal structures of chromosomally encoded Vibrio cholerae antitoxin (VcHigA2), toxin (VcHigB2) and their complex, which show significant differences in structure and mechanisms of function compared to the higBA module from plasmid Rts1, the defining member of the family. The VcHigB2 is more closely related to Escherichia coli RelE both in terms of overall structure and the organization of its active site. VcHigB2 is neutralized by VcHigA2, a modular protein with an N-terminal intrinsically disordered toxin-neutralizing segment followed by a C-terminal helix-turn-helix dimerization and DNA binding domain. VcHigA2 binds VcHigB2 with picomolar affinity, which is mainly a consequence of entropically favorable de-solvation of a large hydrophobic binding interface and enthalpically favorable folding of the N-terminal domain into an alpha-helix followed by a beta-strand. This interaction displaces helix alpha3 of VcHigB2 and at the same time induces a one-residue shift in the register of beta-strand beta3, thereby flipping the catalytically important Arg64 out of the active site.

Ribosome-dependent Vibrio cholerae mRNAse HigB2 is regulated by a beta-strand sliding mechanism.,Hadzi S, Garcia-Pino A, Haesaerts S, Jurenas D, Gerdes K, Lah J, Loris R Nucleic Acids Res. 2017 Feb 28. doi: 10.1093/nar/gkx138. PMID:28334932<ref>PMID:28334932</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5jaa" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Vibrio cholerae O1 biovar El Tor str. N16961]]
[[Category: Hadzi S]]
[[Category: Loris R]]