View source for 3e28


==H. influenzae beta-carbonic anhydrase, variant Y181F==
<StructureSection load='3e28' size='340' side='right' caption='[[3e28]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3e28]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacterium_influenzae"_lehmann_and_neumann_1896 "bacterium influenzae" lehmann and neumann 1896]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3E28 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3E28 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2a8c|2a8c]], [[2a8d|2a8d]], [[3e24|3e24]], [[3e2a|3e2a]], [[3e2w|3e2w]], [[3e2x|3e2x]], [[3e31|3e31]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">can, HI1301 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=727 "Bacterium influenzae" Lehmann and Neumann 1896])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] </span></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=3e28 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3e28 OCA], [http://pdbe.org/3e28 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3e28 RCSB], [http://www.ebi.ac.uk/pdbsum/3e28 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3e28 ProSAT]</span></td></tr>
</table>
== 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/e2/3e28_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=3e28 ConSurf].
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== Publication Abstract from PubMed ==
Haemophilus influenzae beta-carbonic anhydrase (HICA) is hypothesized to be an allosteric protein that is regulated by the binding of bicarbonate ion to a non-catalytic (inhibitory) site that controls the ligation of Asp44 to the catalytically essential zinc ion. We report here the X-ray crystallographic structures of two variants (W39F and Y181F) involved in the binding of bicarbonate ion in the non-catalytic site and an active site variant (D44N) that is incapable of forming a strong zinc ligand. The mutation of Trp39 to Phe increases the apparent Ki for bicarbonate inhibition by 4.8-fold. While the structures of W39F and Y181F are very similar to the wild-type enzyme, the X-ray crystal structure of the D44N variant reveals that it has adopted an active site conformation nearly identical to that of non-allosteric beta-carbonic anhydrases. We propose that the structure of the D44N variant is likely to be representative of the active conformation of the enzyme. These results lend additional support to the hypothesis that HICA is an allosteric enzyme that can adopt active and inactive conformations, the latter of which is stabilized by bicarbonate ion binding to a non-catalytic site.

Allosteric Site Variants of Haemophilus influenzae beta-Carbonic Anhydrase.,Rowlett RS, Tu C, Lee J, Herman AG, Chapnick DA, Shah SH, Gareiss PC Biochemistry. 2009 May 21. PMID:19459702<ref>PMID:19459702</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 3e28" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacterium influenzae lehmann and neumann 1896]]
[[Category: Carbonate dehydratase]]
[[Category: Lee, J]]
[[Category: Rowlett, R S]]
[[Category: Allosteric site mutant]]
[[Category: Beta carbonic anhydrase]]
[[Category: Lyase]]
[[Category: Metal-binding]]