View source for 2jk1


==Crystal structure of the wild-type HupR receiver domain==
<StructureSection load='2jk1' size='340' side='right'caption='[[2jk1]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2jk1]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhodobacter_capsulatus Rhodobacter capsulatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2JK1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2JK1 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=2jk1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2jk1 OCA], [https://pdbe.org/2jk1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2jk1 RCSB], [https://www.ebi.ac.uk/pdbsum/2jk1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2jk1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HUPR_RHOCA HUPR_RHOCA] Probable member of the two-component regulatory system involved in the regulation of the [NiFe] hydrogenase activity. HupR1 is probably phosphorylated by the sensory component and then acts in conjunction with sigma-54 as a transcriptional activator.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/jk/2jk1_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2jk1 ConSurf].
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== Publication Abstract from PubMed ==
Hydrogen uptake protein regulator (HupR) is a member of the nitrogen regulatory protein C (NtrC) family of response regulators. These proteins activate transcription by RNA polymerase (RNAP) in response to a change in environment. This change is detected through the phosphorylation of their receiver domain as part of a two-component signalling pathway. HupR is an unusual member of this family as it activates transcription when unphosphorylated, and transcription is inhibited by phosphorylation. Also, HupR activates transcription through the more general sigma(70) transcription initiation factor, which does not require activation by ATPase, in contrast to other NtrC family members that utilise sigma(54). Hence, its mode of action is expected to be different from those of the more conventional NtrC family members. We have determined the structures of the unphosphorylated N-terminal receiver domain of wild-type HupR, the mutant HupR(D55E)(N) (which cannot be phosphorylated and down-regulated), and HupR in the presence of the phosphorylation mimic BeF(3)(-). The structures show a typical response regulator fold organised as a dimer whose interface involves alpha4-beta5-alpha5 elements. The interactions across the interface are slightly different between apo and phospho mimics, and these reflect a rearrangement of key conserved residues around the active site aspartate that have been implicated in domain activation in other receiver domain proteins. We also show that the wild-type HupR receiver domain forms a weak dimer in solution, which is strengthened in the presence of the phosphorylation mimic BeF(3)(-). The results indicate many features similar to those that have been observed in other systems, including NtrC (where phosphorylation is activatory), and indicate that recognition properties, which allow HupR to be active in the absence of phosphorylation, lie in the transmission of phosphorylation signals through the linker region to the other domains of the protein.

The HupR receiver domain crystal structure in its nonphospho and inhibitory phospho states.,Davies KM, Lowe ED, Venien-Bryan C, Johnson LN J Mol Biol. 2009 Jan 9;385(1):51-64. Epub 2008 Oct 19. PMID:18977359<ref>PMID:18977359</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 2jk1" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rhodobacter capsulatus]]
[[Category: Davies KM]]
[[Category: Johnson LN]]
[[Category: Lowe ED]]
[[Category: Venien-Bryan C]]