View source for 1ibt


==STRUCTURE OF THE D53,54N MUTANT OF HISTIDINE DECARBOXYLASE AT-170 C==
<StructureSection load='1ibt' size='340' side='right'caption='[[1ibt]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ibt]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Lactobacillus_sp._30A Lactobacillus sp. 30A]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IBT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IBT 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</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=1ibt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ibt OCA], [https://pdbe.org/1ibt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ibt RCSB], [https://www.ebi.ac.uk/pdbsum/1ibt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ibt ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/DCHS_LACS3 DCHS_LACS3] 
== 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/ib/1ibt_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1ibt ConSurf].
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== Publication Abstract from PubMed ==
Histidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth. HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH. The X-ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate-binding site. The HDC trimer has also been shown to exhibit cooperative kinetics at neutral pH, that is, histidine can trigger a T-state to R-state transition. The D53,54N mutant of HDC has an elevated Km, even at low pH, indicating that the enzyme assumes the low activity T-state. We have solved the structures of the D53,54N mutant at low pH, with and without the substrate analog histidine methyl ester (HME) bound. Structural analysis shows that the apo-D53,54N mutant is in the inactive or T-state and that binding of the substrate analog induces the enzyme to adopt the active or R-state. A mechanism for the cooperative transition is proposed.

Structure and cooperativity of a T-state mutant of histidine decarboxylase from Lactobacillus 30a.,Worley S, Schelp E, Monzingo AF, Ernst S, Robertus JD Proteins. 2002 Feb 15;46(3):321-9. PMID:11835507<ref>PMID:11835507</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Lactobacillus sp. 30A]]
[[Category: Large Structures]]
[[Category: Ernst S]]
[[Category: Monzingo AF]]
[[Category: Robertus JD]]
[[Category: Schelp E]]
[[Category: Worley S]]