4q7e

<StructureSection load='4q7e' size='340' side='right' caption='[[4q7e]], [[Resolution|resolution]] 1.44&Aring;' scene=''>

<table><tr><td colspan='2'>[[4q7e]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4Q7E OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4Q7E FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></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=4q7e FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4q7e OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4q7e RCSB], [http://www.ebi.ac.uk/pdbsum/4q7e PDBsum]</span></td></tr>

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== Publication Abstract from PubMed ==

Several Leptospira species cause leptospirosis, the most extended zoonosis worldwide. In bacteria, two-component systems constitute key signalling pathways, some of which are involved in pathogenesis. The physiological roles of two-component systems in Leptospira are largely unknown, despite identifying several dozens within their genomes. Biochemical confirmation of an operative phosphorelaying two-component system has been obtained so far only for the Hklep/Rrlep pair. It is known that hklep/rrlep knockout strains of Leptospira biflexa result in haem auxotrophy, although their de novo biosynthesis machinery remains fully functional. Haem is essential for Leptospira, but information about Hklep/Rrlep effector function(s) and target(s) is still lacking. We are now reporting a thorough molecular characterization of this system, which we rename HemK/HemR. The DNA HemR-binding motif was determined, and found within the genomes of saprophyte and pathogenic Leptospira. In this way, putative HemR-regulated genes were pinpointed, including haem catabolism-related (hmuO - haem oxygenase) and biosynthesis-related (the hemA/C/D/B/L/E/N/G operon). Specific HemR binding to these two promoters was quantified, and a dual function was observed in vivo, inversely repressing the hmuO, while activating the hemA operon transcription. The crystal structure of HemR receiver domain was determined, leading to a mechanistic model for its dual regulatory role.

HemR is an OmpR/PhoB-like response regulator from Leptospira, which simultaneously effects transcriptional activation and repression of key haem metabolism genes.,Morero NR, Botti H, Nitta KR, Carrion F, Obal G, Picardeau M, Buschiazzo A Mol Microbiol. 2014 Oct;94(2):340-52. doi: 10.1111/mmi.12763. Epub 2014 Sep 15. PMID:25145397<ref>PMID:25145397</ref>

== References ==

[[Category: Buschiazzo, A.]]

[[Category: Morero, N R.]]

[[Category: Dna binding protein]]

[[Category: Signaling protein]]