View source for 4ua2


==Crystal structure of dual function transcriptional regulator MerR from Bacillus megaterium MB1==
<StructureSection load='4ua2' size='340' side='right'caption='[[4ua2]], [[Resolution|resolution]] 2.61&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ua2]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Priestia_megaterium Priestia megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4UA2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4UA2 FirstGlance]. <br>
</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=4ua2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ua2 OCA], [https://pdbe.org/4ua2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ua2 RCSB], [https://www.ebi.ac.uk/pdbsum/4ua2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ua2 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q799U3_PRIMG Q799U3_PRIMG] Mediates the mercuric-dependent induction of mercury resistance operon. In the absence of mercury MerR represses transcription by binding tightly to the mer operator region; when mercury is present the dimeric complex binds a single ion and becomes a potent transcriptional activator, while remaining bound to the mer site.[ARBA:ARBA00024874]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The mer operon confers bacterial resistance to inorganic mercury (Hg2+) and organomercurials by encoding proteins involved in sensing, transport and detoxification of these cytotoxic agents. Expression of the mer operon is under tight control by the dual-function transcriptional regulator MerR. The metal-free, apo MerR binds to the mer operator/promoter region as a repressor to block transcription initiation, but is converted into an activator upon Hg2+-binding. To understand how MerR interacts with Hg2+ and how Hg2+-binding modulates MerR function, we report here the crystal structures of apo and Hg2+-bound MerR from Bacillus megaterium, corresponding respectively to the repressor and activator conformation of MerR. To our knowledge, the apo-MerR structure represents the first visualization of a MerR family member in its intact and inducer-free form. And the Hg2+-MerR structure offers the first view of a triligated Hg2+-thiolate center in a metalloprotein, confirming that MerR binds Hg2+ via trigonal planar coordination geometry. Structural comparison revealed the conformational transition of MerR is coupled to the assembly/disassembly of a buried Hg2+ binding site, thereby providing a structural basis for the Hg2+-mediated functional switching of MerR. The pronounced Hg2+-induced repositioning of the MerR DNA-binding domains suggests a plausible mechanism for the transcriptional regulation of the mer operon.

Structural basis of the mercury(II)-mediated conformational switching of the dual-function transcriptional regulator MerR.,Chang CC, Lin LY, Zou XW, Huang CC, Chan NL Nucleic Acids Res. 2015 Jul 6. pii: gkv681. PMID:26150423<ref>PMID:26150423</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ua2" style="background-color:#fffaf0;"></div>

==See Also==
*[[Transcriptional activator 3D structures|Transcriptional activator 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Priestia megaterium]]
[[Category: Chan NL]]
[[Category: Chang CC]]
[[Category: Huang CC]]
[[Category: Lin LY]]
[[Category: Zou XW]]