View source for 4eac


==Crystal structure of mannonate dehydratase from Escherichia coli strain K12==
<StructureSection load='4eac' size='340' side='right' caption='[[4eac]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4eac]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EAC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4EAC FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1tz9|1tz9]], [[3fvm|3fvm]], [[3dbn|3dbn]], [[4eay|4eay]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">uxuA, b4322, JW4285 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 ECOLI])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Mannonate_dehydratase Mannonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.8 4.2.1.8] </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=4eac FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4eac OCA], [http://pdbe.org/4eac PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4eac RCSB], [http://www.ebi.ac.uk/pdbsum/4eac PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4eac ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/UXUA_ECOLI UXUA_ECOLI]] Catalyzes the dehydration of D-mannonate.<ref>PMID:3038546</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Mannonate dehydratase (ManD; EC4.2.1.8) catalyzes the dehydration of D-mannonate to 2-keto-3-deoxygluconate. It is the third enzyme in the pathway for dissimilation of D-glucuronate to 2-keto-3-deoxygluconate involving in the Entner-Doudoroff pathway in certain bacterial and archaeal species. ManD from Gram negative bacteria has an insert sequence as compared to those from Gram positives revealed by sequence analysis. To evaluate the impact of this insert sequence on the catalytic efficiency, we solved the crystal structures of ManD from Escherichia coli strain K12 and its complex with D-mannonate, which reveal that this insert sequence forms two alpha helices locating above the active site. The two insert alpha helices introduce a loop that forms a cap covering the substrate binding pocket, which restricts the tunnels of substrate entering and product releasing from the active site. Site-directed mutations and enzymatic activity assays confirm that the catalytic rate is decreased by this loop. These features are conserved among Gram negative bacteria. Thus, the insert sequence of ManD from Gram negative bacteria acts as a common inducer to decrease the catalytic rate and consequently the glucuronate metabolic rate as compared to those from Gram positives. Moreover, residues essential for substrate to enter the active site were characterized via structural analysis and enzymatic activity assays.

Structural insights into decreased enzymatic activity induced by an insert sequence in mannonate dehydratase from Gram negative bacterium.,Qiu X, Tao Y, Zhu Y, Yuan Y, Zhang Y, Liu H, Gao Y, Teng M, Niu L J Struct Biol. 2012 Nov;180(2):327-34. doi: 10.1016/j.jsb.2012.06.013. Epub 2012 , Jul 14. PMID:22796868<ref>PMID:22796868</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4eac" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Ecoli]]
[[Category: Mannonate dehydratase]]
[[Category: Gao, Y]]
[[Category: Liu, H]]
[[Category: Niu, L]]
[[Category: Qiu, X]]
[[Category: Teng, M]]
[[Category: Yuan, Y]]
[[Category: Zhang, Y]]
[[Category: Zhu, Y]]
[[Category: Dehydratase]]
[[Category: Lyase]]
[[Category: Tim barrel]]