View source for 2ml3


==Solution Structure of AlgE6R3 subunit from the Azotobacter vinelandii Mannuronan C5-epimerase==
<StructureSection load='2ml3' size='340' side='right'caption='[[2ml3]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ml3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ML3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ML3 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=2ml3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ml3 OCA], [https://pdbe.org/2ml3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ml3 RCSB], [https://www.ebi.ac.uk/pdbsum/2ml3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ml3 ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/ALGE6_AZOVI ALGE6_AZOVI] Converts beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G), producing a polymer with gel-forming capacity, required for the formation of the cyst coat.
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== Publication Abstract from PubMed ==
The bacterium Azotobacter vinelandii produces a family of seven secreted and calcium-dependent mannuronan C-5 epimerases (AlgE1-7). These epimerases are responsible for the epimerization of beta-d-mannuronic acid (M) to alpha-l-guluronic acid (G) in alginate polymers. The epimerases display a modular structure composed of one or two catalytic A-modules and from one to seven R-modules having an activating effect on the A-module. In this study, we have determined the NMR structure of the three individual R-modules from AlgE6 (AR1R2R3) and the overall structure of both AlgE4 (AR) and AlgE6 using small angle x-ray scattering. Furthermore, the alginate binding ability of the R-modules of AlgE4 and AlgE6 has been studied with NMR and isothermal titration calorimetry. The AlgE6 R-modules fold into an elongated parallel beta-roll with a shallow, positively charged groove across the module. Small angle x-ray scattering analyses of AlgE4 and AlgE6 show an overall elongated shape with some degree of flexibility between the modules for both enzymes. Titration of the R-modules with defined alginate oligomers shows strong interaction between AlgE4R and both oligo-M and MG, whereas no interaction was detected between these oligomers and the individual R-modules from AlgE6. A combination of all three R-modules from AlgE6 shows weak interaction with long M-oligomers. Exchanging the R-modules between AlgE4 and AlgE6 resulted in a novel epimerase called AlgE64 with increased G-block forming ability compared with AlgE6.

Structural and Functional Characterization of the R-modules in Alginate C-5 Epimerases AlgE4 and AlgE6 from Azotobacter vinelandii.,Buchinger E, Knudsen DH, Behrens MA, Pedersen JS, Aarstad OA, Tondervik A, Valla S, Skjak-Braek G, Wimmer R, Aachmann FL J Biol Chem. 2014 Nov 7;289(45):31382-96. doi: 10.1074/jbc.M114.567008. Epub 2014, Sep 29. PMID:25266718<ref>PMID:25266718</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Azotobacter vinelandii]]
[[Category: Large Structures]]
[[Category: Aachmann FL]]
[[Category: Buchinger E]]
[[Category: Wimmer R]]