2pyh

<StructureSection load='2pyh' size='340' side='right' caption='[[2pyh]], [[Resolution|resolution]] 2.70&Aring;' scene=''>

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

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MAV:ALPHA-D-MANNOPYRANURONIC+ACID'>MAV</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2pyg|2pyg]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">algE4 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=354 Azotobacter vinelandii])</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=2pyh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pyh OCA], [http://pdbe.org/2pyh PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2pyh RCSB], [http://www.ebi.ac.uk/pdbsum/2pyh PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2pyh ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/ALGE4_AZOVI ALGE4_AZOVI]] Converts beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G), but introduces almost exclusively MG blocks, producing a polymer with non-gel-forming capacity.

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== Publication Abstract from PubMed ==

Alginate is a family of linear copolymers of (1--&gt;4)-linked beta-d-mannuronic acid and its C-5 epimer alpha-l-guluronic acid. The polymer is first produced as polymannuronic acid and the guluronic acid residues are then introduced at the polymer level by mannuronan C-5-epimerases. The structure of the catalytic A-module of the Azotobacter vinelandii mannuronan C-5-epimerase AlgE4 has been determined by x-ray crystallography at 2.1-A resolution. AlgE4A folds into a right-handed parallel beta-helix structure originally found in pectate lyase C and subsequently in several polysaccharide lyases and hydrolases. The beta-helix is composed of four parallel beta-sheets, comprising 12 complete turns, and has an amphipathic alpha-helix near the N terminus. The catalytic site is positioned in a positively charged cleft formed by loops extending from the surface encompassing Asp(152), an amino acid previously shown to be important for the reaction. Site-directed mutagenesis further implicates Tyr(149), His(154), and Asp(178) as being essential for activity. Tyr(149) probably acts as the proton acceptor, whereas His(154) is the proton donor in the epimerization reaction.

Structural and mutational characterization of the catalytic A-module of the mannuronan C-5-epimerase AlgE4 from Azotobacter vinelandii.,Rozeboom HJ, Bjerkan TM, Kalk KH, Ertesvag H, Holtan S, Aachmann FL, Valla S, Dijkstra BW J Biol Chem. 2008 Aug 29;283(35):23819-28. Epub 2008 Jun 23. PMID:18574239<ref>PMID:18574239</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 2pyh" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Aachman, F L]]

[[Category: Bjerkan, T M]]

[[Category: Dijkstra, B W]]

[[Category: Ertesvag, H]]

[[Category: Holtan, S]]

[[Category: Kalk, K H]]

[[Category: Rozeboom, H J]]

[[Category: Valla, S]]

[[Category: Mannuronic acid]]