3e3g

<table><tr><td colspan='2'>[[3e3g]] is a 6 chain structure with sequence from [https://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=3E3G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3E3G FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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"><div style='overflow: auto; max-height: 3em;'>[[2a8c|2a8c]], [[2a8d|2a8d]], [[3e24|3e24]], [[3e28|3e28]], [[3e2a|3e2a]], [[3e2w|3e2w]], [[3e2x|3e2x]], [[3e31|3e31]], [[3e3f|3e3f]], [[3e3i|3e3i]]</div></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">can, HI1301 ([https://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'>[https://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] </span></td></tr>

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== Publication Abstract from PubMed ==

The Haemophilus influenzae beta-carbonic anhydrase (HICA) allosteric site variants V47A and G41A were overexpressed and purified to homogeneity. These variants have k(cat)/K(m) values similar to that of the wild-type enzyme and exhibit a similar dramatic decrease in catalytic activity at pH &lt;8.0. However, both HICA-G41A and -V47A were serendipitously found to bind sulfate ion or bicarbonate ion near pairs of Glu50 and Arg64 residues located on the dimerization interface. In the case of HICA-V47A, bicarbonate ions simultaneously bind to both the dimerization interface and the allosteric sites. For HICA-G41A, two of 12 chains in the asymmetric unit bind bicarbonate ion exclusively at the dimerization interface, while the remaining 10 chains bind bicarbonate ion exclusively at the allosteric site. We propose that the new anion binding site along the dimerization interface of HICA is an "escort" site that represents an intermediate along the ingress and egress route of bicarbonate ion to and from the allosteric binding site, respectively. The structural evidence for sulfate binding at the escort site suggests that the mechanism of sulfate activation of HICA is the result of sulfate ion competing for bicarbonate at the escort site, preventing passage of bicarbonate from the bulk solution to its allosteric site.

Evidence for a bicarbonate "escort" site in Haemophilus influenzae beta-carbonic anhydrase .,Rowlett RS, Hoffmann KM, Failing H, Mysliwiec MM, Samardzic D Biochemistry. 2010 May 4;49(17):3640-7. PMID:20359198<ref>PMID:20359198</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 3e3g" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Bacterium influenzae lehmann and neumann 1896]]

[[Category: Carbonate dehydratase]]

[[Category: Failing, H]]

[[Category: Rowlett, R S]]

[[Category: Metal-binding]]