3bc9

<table><tr><td colspan='2'>[[3bc9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Haloh Haloh]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BC9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BC9 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACI:6-AMINO-4-HYDROXYMETHYL-CYCLOHEX-4-ENE-1,2,3-TRIOL'>ACI</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=G6D:6-DEOXY-ALPHA-D-GLUCOSE'>G6D</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=GLD:4,6-DIDEOXYGLUCOSE'>GLD</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3bcd|3bcd]], [[3bcf|3bcf]]</div></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] </span></td></tr>

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== Publication Abstract from PubMed ==

The gene for a membrane-bound, halophilic, and thermostable alpha-amylase, AmyB, from Halothermothrix orenii was cloned and sequenced. The crystal structure shows that, in addition to the typical domain organization of family 13 glycoside hydrolases, AmyB carries an additional N-terminal domain (N domain) that forms a large groove--the N-C groove--some 30 A away from the active site. The structure of AmyB with the inhibitor acarbose at 1.35 A resolution shows that a nonasaccharide has been synthesized through successive transglycosylation reactions of acarbose. Unexpectedly, in a complex of wild-type AmyB with alpha-cyclodextrin and maltoheptaose at 2.2 A resolution, a maltotetraose molecule is bound in subsites -1 to +3, spanning the cleavage point at -1/+1, with the -1 glucosyl residue present as a (2)S(o) skew boat. This wild-type AmyB complex was obtained in the presence of a large excess of substrate, a condition under which it is possible to capture Michaelis complexes, which may explain the observed binding across -1/+1 and ring distortion. We observe three methionine side chains that serve as "binding platforms" for glucosyl rings in AmyB, a seemingly rare occurrence in carbohydrate-binding proteins. The structures and results from the biochemical characterization of AmyB and AmyB lacking the N domain show that the N domain increases binding of the enzyme to raw starch. Furthermore, theoretical modeling suggests that the N-C groove can accommodate, spatially and chemically, large substrates such as A-starch.

Crystal structure of the polyextremophilic alpha-amylase AmyB from Halothermothrix orenii: details of a productive enzyme-substrate complex and an N domain with a role in binding raw starch.,Tan TC, Mijts BN, Swaminathan K, Patel BK, Divne C J Mol Biol. 2008 May 9;378(4):852-70. Epub 2008 Feb 29. PMID:18387632<ref>PMID:18387632</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 3bc9" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Alpha-amylase]]

[[Category: Haloh]]

[[Category: Divne, C]]

[[Category: Mijts, B N]]

[[Category: Patel, B K.C]]

[[Category: Swaminathan, K]]

[[Category: Tan, T C]]

[[Category: Thermostable]]