View source for 8q2h


==beta-galactosidase from Bacillus circulans==
<StructureSection load='8q2h' size='340' side='right'caption='[[8q2h]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8q2h]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Niallia_circulans_subsp._circulans Niallia circulans subsp. circulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8Q2H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8Q2H FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.2&#8491;</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=8q2h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8q2h OCA], [https://pdbe.org/8q2h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8q2h RCSB], [https://www.ebi.ac.uk/pdbsum/8q2h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8q2h ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/E5RWQ2_NIACI E5RWQ2_NIACI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
beta-Galactosidase from Bacillus circulans ATCC 31382 (BgaD) is a biotechnologically important enzyme for the synthesis of beta-galactooligosaccharides (GOS). Among its four isoforms, isoform A (BgaD-A) has distinct synthetic properties. Here, we present cryoelectron microscopy (cryo-EM) structures of BgaD-A and compare them with the known X-ray crystal structure of isoform D (BgaD-D), revealing substantial structural divergences between the two isoforms. In contrast to BgaD-D, BgaD-A features a flexible Big-4 domain and another enigmatic domain. The newly identified flexible region in BgaD-A is termed as "barrier domain 8," and serves as a barricade, obstructing the access of longer oligosaccharide substrates into the active site of BgaD-A. The transgalactosylation reactions catalyzed by both isoforms revealed that BgaD-A has a higher selectivity than BgaD-D in the earlier stages of the reaction and is prevailingly directed to shorter galactooligosaccharides. This study improves our understanding of the structural determinants governing beta-galactosidase catalysis, with implications for tailored GOS production.

The variable structural flexibility of the Bacillus circulans beta-galactosidase isoforms determines their unique functionalities.,Hovorkova M, Kascakova B, Petraskova L, Havlickova P, Novacek J, Pinkas D, Gardian Z, Kren V, Bojarova P, Smatanova IK Structure. 2024 Sep 26:S0969-2126(24)00374-5. doi: 10.1016/j.str.2024.09.005. PMID:39353423<ref>PMID:39353423</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8q2h" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Niallia circulans subsp. circulans]]
[[Category: Bojarova P]]
[[Category: Gardian Z]]
[[Category: Hovorkova M]]
[[Category: Kascakova B]]
[[Category: Kren V]]
[[Category: Kuta Smatanova I]]
[[Category: Novacek J]]
[[Category: Petraskova L]]
[[Category: Pinkas D]]