3a6o

<table><tr><td colspan='2'>[[3a6o]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_43649 Atcc 43649]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1vfk 1vfk]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3A6O OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=3A6O FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ARE:ACARBOSE+DERIVED+PENTASACCHARIDE'>ARE</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Neopullulanase Neopullulanase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.135 3.2.1.135] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=3a6o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3a6o OCA], [http://pdbe.org/3a6o PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3a6o RCSB], [http://www.ebi.ac.uk/pdbsum/3a6o PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3a6o ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/NEPU2_THEVU NEPU2_THEVU]] Hydrolyzes pullulan efficiently but only a small amount of starch. Endohydrolysis of 1,4-alpha-glucosidic linkages in pullulan to form panose. Cleaves also (1-6)-alpha-glucosidic linkages to form maltotriose.

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) has the unique ability to hydrolyze cyclodextrins (CDs), with various sized cavities, as well as starch. To understand the relationship between structure and substrate specificity, x-ray structures of a TVAII-acarbose complex and inactive mutant TVAII (D325N/D421N)/alpha-, beta- and gamma-CDs complexes were determined at resolutions of 2.9, 2.9, 2.8, and 3.1 A, respectively. In all complexes, the interactions between ligands and enzymes at subsites -1, -2, and -3 were almost the same, but striking differences in the catalytic site structure were found at subsites +1 and +2, where Trp(356) and Tyr(374) changed the conformation of the side chain depending on the structure and size of the ligands. Trp(356) and Tyr(374) are thought to be responsible for the multiple substrate-recognition mechanism of TVAII, providing the unique substrate specificity. In the beta-CD complex, the beta-CD maintains a regular conical structure, making it difficult for Glu(354) to protonate the O-4 atom at the hydrolyzing site as a previously proposed hydrolyzing mechanism of alpha-amylase. From the x-ray structures, it is suggested that the protonation of the O-4 atom is possibly carried out via a hydrogen atom of the inter-glucose hydrogen bond at the hydrolyzing site.

Complex structures of Thermoactinomyces vulgaris R-47 alpha-amylase 2 with acarbose and cyclodextrins demonstrate the multiple substrate recognition mechanism.,Ohtaki A, Mizuno M, Tonozuka T, Sakano Y, Kamitori S J Biol Chem. 2004 Jul 23;279(30):31033-40. Epub 2004 May 11. PMID:15138257<ref>PMID:15138257</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 3a6o" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Atcc 43649]]

[[Category: Neopullulanase]]

[[Category: Kamitori, S]]

[[Category: Mizuno, M]]

[[Category: Ohtaki, A]]

[[Category: Sakano, Y]]

[[Category: Tonozuka, T]]

[[Category: Metal-binding]]