1ibv

<table><tr><td colspan='2'>[[1ibv]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Lacs3 Lacs3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IBV OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1IBV FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PVH:HISTIDINE-METHYL-ESTER'>PVH</scene>, <scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1pya|1pya]], [[1hq6|1hq6]], [[1ibt|1ibt]], [[1ibu|1ibu]], [[1ibw|1ibw]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HDCA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1593 LACS3])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Histidine_decarboxylase Histidine decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.22 4.1.1.22] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1ibv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ibv OCA], [http://pdbe.org/1ibv PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ibv RCSB], [http://www.ebi.ac.uk/pdbsum/1ibv PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ibv ProSAT]</span></td></tr>

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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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<div class="pdbe-citations 1ibv" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Histidine decarboxylase]]

[[Category: Lacs3]]

[[Category: Ernst, S]]

[[Category: Monzingo, A F]]

[[Category: Robertus, J D]]

[[Category: Schelp, E]]

[[Category: Worley, S]]

[[Category: Substrate-induced activation]]