View source for 7ewd


==Mycobacterium tuberculosis HigA2 (Form II)==
<StructureSection load='7ewd' size='340' side='right'caption='[[7ewd]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7ewd]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis_H37Rv Mycobacterium tuberculosis H37Rv]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7EWD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7EWD 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]] 3.2&#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=7ewd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ewd OCA], [https://pdbe.org/7ewd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ewd RCSB], [https://www.ebi.ac.uk/pdbsum/7ewd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ewd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HIGA2_MYCTU HIGA2_MYCTU] Putative antitoxin component of a type II toxin-antitoxin (TA) system. Its cognate toxin would be HigB2.<ref>PMID:24662523</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Transcription factors are the primary regulators of gene expression and recognize specific DNA sequences under diverse physiological conditions. Although they are vital for many important cellular processes, it remains unclear when and how transcription factors and DNA interact. The antitoxin from a toxin-antitoxin system is an example of negative transcriptional autoregulation: during expression of the cognate toxin it is suppressed through binding to a specific DNA sequence. In the present study, the antitoxin HigA2 from Mycobacterium tuberculosis M37Rv was structurally examined. The crystal structure of M. tuberculosis HigA2 comprises three sections: an N-terminal autocleavage region, an alpha-helix bundle which contains an HTH motif, and a C-terminal beta-lid. The N-terminal region is responsible for toxin binding, but was shown to cleave spontaneously in its absence. The HTH motif performs a key role in DNA binding, with the C-terminal beta-lid influencing the interaction by mediating the distance between the motifs. However, M. tuberculosis HigA2 exhibits a unique coordination of the HTH motif and no DNA-binding activity is detected. Three crystal structures of M. tuberculosis HigA2 show a flexible alignment of the HTH motif, which implies that the motif undergoes structural rearrangement to interact with DNA. This study reveals the molecular mechanisms of how transcription factors interact with partner proteins or DNA.

Chasing the structural diversity of the transcription regulator Mycobacterium tuberculosis HigA2.,Richardson W, Kang GW, Lee HJ, Kwon KM, Kim S, Kim HJ IUCrJ. 2021 Aug 24;8(Pt 5):823-832. doi: 10.1107/S2052252521007715. eCollection, 2021 Sep 1. PMID:34584743<ref>PMID:34584743</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 7ewd" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis H37Rv]]
[[Category: Kim HJ]]