View source for 6seb


==Cold-adapted beta-D-galactosidase from Arthrobacter sp. 32cB in complex with IPTG==
<StructureSection load='6seb' size='340' side='right'caption='[[6seb]], [[Resolution|resolution]] 2.27&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6seb]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Arthrobacter_sp._32cb Arthrobacter sp. 32cb]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6SEB OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6SEB FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=IPT:ISOPROPYL-1-BETA-D-THIOGALACTOSIDE'>IPT</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-galactosidase Beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.23 3.2.1.23] </span></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=6seb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6seb OCA], [http://pdbe.org/6seb PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6seb RCSB], [http://www.ebi.ac.uk/pdbsum/6seb PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6seb ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
ArthbetaDG is a dimeric, cold-adapted beta-d-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The resulting three-dimensional structures of complexes: ArthbetaDG_E441Q/LACs and ArthbetaDG/IPTG (ligand bound in shallow mode) and structures of complexes ArthbetaDG_E441Q/LACd, ArthbetaDG/ONPG (ligands bound in deep mode), and galactose ArthbetaDG/GAL and their analysis enabled structural characterization of the hydrolysis reaction mechanism. Furthermore, comparative analysis with mesophilic analogs revealed the most striking differences in catalysis mechanisms. The key role in substrate transfer from shallow to deep binding mode involves rotation of the F581 side chain. It is worth noting that the 10-aa loop restricting access to the active site in mesophilic GH2 betaDGs, in ArthbetaDG is moved outward. This facilitates access of substrate to active site. Such a permanent exposure of the entrance to the active site may be a key factor for improved turnover rate of the cold adapted enzyme and thus a structural feature related to its cold adaptation.

Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-d-galactosidase from Arthrobacter sp. 32cB.,Rutkiewicz M, Bujacz A, Wanarska M, Wierzbicka-Wos A, Cieslinski H Int J Mol Sci. 2019 Sep 3;20(17). pii: ijms20174301. doi: 10.3390/ijms20174301. PMID:31484304<ref>PMID:31484304</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6seb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arthrobacter sp. 32cb]]
[[Category: Beta-galactosidase]]
[[Category: Large Structures]]
[[Category: Bujacz, A]]
[[Category: Bujacz, G]]
[[Category: Kaminska, P]]
[[Category: Rutkiewicz, M]]
[[Category: Cold-adapted]]
[[Category: Dimeric]]
[[Category: Galactosidase]]
[[Category: Hydrolase]]
[[Category: Psychrophilic]]