View source for 4o8o


==Crystal structure of SthAraf62A, a GH62 family alpha-L-arabinofuranosidase from Streptomyces thermoviolaceus, bound to alpha-L-arabinose==
<StructureSection load='4o8o' size='340' side='right'caption='[[4o8o]], [[Resolution|resolution]] 1.21&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4o8o]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_thermoviolaceus Streptomyces thermoviolaceus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4O8O OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4O8O FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.21&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AHR:ALPHA-L-ARABINOFURANOSE'>AHR</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></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=4o8o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4o8o OCA], [https://pdbe.org/4o8o PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4o8o RCSB], [https://www.ebi.ac.uk/pdbsum/4o8o PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4o8o ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q76BV4_STRTL Q76BV4_STRTL] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Xylan debranching enzymes facilitate the complete hydrolysis of xylan and can be used to alter xylan chemistry. Herein, the GH62 family alpha-l-arabinofuranosidase from Streptomyces thermoviolaceus (SthAbf62A) was shown to have a half-life of 60 min at 60 degrees C, and ability to cleave alpha-1,3 l-arabinofuranose (l-Araf ) from singly-substituted xylopyranosyl (Xylp) backbone residues in wheat arabinoxylan; low activity towards arabinan as well as 4-nitrophenyl alpha-l-arabinofuranoside was also detected. After selectively removing alpha-1,3 l-Araf substituents from di-substituted Xylp residues present in wheat arabinoxylan, SthAbf62A could also cleave the remaining alpha-1,2 l-Araf substituents, confirming the ability of SthAbf62A to remove alpha-l-Araf residues that are (1--&gt;2) and (1--&gt;3) linked to mono-substituted beta-d-Xylp sugars. Three-dimensional structures of SthAbf62A and its complex with xylotetraose and l-arabinose confirmed a five-bladed beta-propeller fold and revealed a molecular Velcro in blade V between the beta1 and beta21 strands, a disulfide bond between Cys 27 and Cys 297, and a calcium ion coordinated in the central channel of the fold. The enzyme-arabinose complex structure further revealed a narrow and seemingly rigid l-arabinose binding pocket situated at the center of one side of the beta propeller, which stabilized the arabinofuranosyl substituent through several hydrogen-bonding and hydrophobic interactions. The predicted catalytic amino acids were oriented towards this binding pocket and the catalytic essentiality of Asp53 and Glu213 was confirmed by site-specific mutagenesis. Complex structures with xylotetraose revealed a shallow cleft for xylan backbone binding which is open at both ends and comprises multiple binding subsites above and flanking the l-arabinose binding pocket.

Biochemical and structural characterization of a thermostable family GH62 alpha-l-arabinofuranosidase from Streptomyces thermoviolaceus to elucidate the molecular basis for activity towards arabinoxylan.,Wang W, Mai-Gisondi G, Stogios PJ, Kaur A, Xu X, Cui H, Turunen O, Savchenko A, Master ER Appl Environ Microbiol. 2014 Jun 20. pii: AEM.00685-14. PMID:24951792<ref>PMID:24951792</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4o8o" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces thermoviolaceus]]
[[Category: Cui H]]
[[Category: Master E]]
[[Category: Savchenko A]]
[[Category: Stogios PJ]]
[[Category: Wang W]]
[[Category: Xu X]]