1bf2

</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='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Isoamylase Isoamylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.68 3.2.1.68] </span></td></tr>

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== Publication Abstract from PubMed ==

The three-dimensional structure of isoamylase from Pseudomonas amyloderamosa, which hydrolyzes alpha-1,6-glucosidic linkages of amylopectin and glycogen, has been determined by X-ray structure analysis. The enzyme has 750 amino acid residues and a molecular mass of 80 kDa, and it can be crystallized from ammonium sulfate solution. The structure was elucidated by the multiple isomorphous replacement method and refined at 2.2 A resolution, resulting in a final R-factor of 0.161 for significant reflections with a root-mean-square deviation from ideality in bond lengths of 0.009 A. The analysis revealed that in the N-terminal region, isoamylase has a novel extra domain that we call domain N, whose three-dimensional structure has not so far been reported. It has a (beta/alpha)8-barrel-type supersecondary structure in the catalytic domain common to the alpha-amylase family enzymes, though the barrel is incomplete, with a deletion of an alpha-helix between the fifth and sixth beta-strands. A long excursed region is present between the third beta-strand and the third alpha-helix of the barrel but, in contrast to the so-called domain B that has been identified in the other enzymes of alpha-amylase family, it cannot be considered to be an independent domain, because this loop forms a globular cluster together with the loop between the fourth beta-strand and the fourth alpha-helix. Isoamylase contains a bound calcium ion, but this is not in the same position as the conserved calcium ion that has been reported in other alpha-amylase family enzymes.

Three-dimensional structure of Pseudomonas isoamylase at 2.2 A resolution.,Katsuya Y, Mezaki Y, Kubota M, Matsuura Y J Mol Biol. 1998 Sep 4;281(5):885-97. PMID:9719642<ref>PMID:9719642</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 1bf2" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Isoamylase]]

[[Category: Katsuya, Y]]

[[Category: Kubota, M]]

[[Category: Matsuura, Y]]

[[Category: Mezaki, Y]]

[[Category: Hydrolase]]