View source for 4cmr


==The crystal structure of novel exo-type maltose-forming amylase(Py04_0872) from Pyrococcus sp. ST04==
<StructureSection load='4cmr' size='340' side='right'caption='[[4cmr]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4cmr]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_sp._ST04 Pyrococcus sp. ST04]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4CMR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4CMR FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=4cmr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4cmr OCA], [https://pdbe.org/4cmr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4cmr RCSB], [https://www.ebi.ac.uk/pdbsum/4cmr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4cmr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/I3RE04_9EURY I3RE04_9EURY] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
A novel maltose-forming alpha-amylase (PSMA) was recently found in the hyperthermophilic archaeon Pyrococcus sp. ST04. This enzyme shows &lt;13% amino-acid sequence identity to other known alpha-amylases and displays a unique enzymatic property in that it hydrolyzes both alpha-1,4-glucosidic and alpha-1,6-glucosidic linkages of substrates, recognizing only maltose units, in an exo-type manner. Here, the crystal structure of PSMA at a resolution of 1.8 A is reported, showing a tight ring-shaped tetramer with monomers composed of two domains: an N-domain (amino acids 1-341) with a typical GH57 family (beta/alpha)7-barrel fold and a C-domain (amino acids 342-597) composed of alpha-helical bundles. A small closed cavity observed in proximity to the catalytic residues Glu153 and Asp253 at the domain interface has the appropriate volume and geometry to bind a maltose unit, accounting for the selective exo-type maltose hydrolysis of the enzyme. A narrow gate at the putative subsite +1 formed by residue Phe218 and Phe452 is essential for specific cleavage of glucosidic bonds. The closed cavity at the active site is connected to a short substrate-binding channel that extends to the central hole of the tetramer, exhibiting a geometry that is significantly different from classical maltogenic amylases or beta-amylases. The structural features of this novel exo-type maltose-forming alpha-amylase provide a molecular basis for its unique enzymatic characteristics and for its potential use in industrial applications and protein engineering.

Structural features underlying the selective cleavage of a novel exo-type maltose-forming amylase from Pyrococcus sp. ST04.,Park KH, Jung JH, Park SG, Lee ME, Holden JF, Park CS, Woo EJ Acta Crystallogr D Biol Crystallogr. 2014 Jun;70(Pt 6):1659-68. doi:, 10.1107/S1399004714006567. Epub 2014 May 30. PMID:24914977<ref>PMID:24914977</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4cmr" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Pyrococcus sp. ST04]]
[[Category: Jung J-H]]
[[Category: Park C-S]]
[[Category: Park K-H]]
[[Category: Woo E-J]]