1uhv: Difference between revisions

Revision as of 11:15, 3 May 2008

Crystal structure of beta-D-xylosidase from Thermoanaerobacterium saccharolyticum, a family 39 glycoside hydrolase

OverviewOverview

1,4-beta-D-Xylan is the major component of plant cell-wall hemicelluloses. beta-D-Xylosidases are involved in the breakdown of xylans into xylose and belong to families 3, 39, 43, 52, and 54 of glycoside hydrolases. Here, we report the first crystal structure of a member of family 39 glycoside hydrolase, i.e. beta-D-xylosidase from Thermoanaerobacterium saccharolyticum strain B6A-RI. This study also represents the first structure of any beta-xylosidase of the above five glycoside hydrolase families. Each monomer of T. saccharolyticum beta-xylosidase comprises three distinct domains; a catalytic domain of the canonical (beta/alpha)(8)-barrel fold, a beta-sandwich domain, and a small alpha-helical domain. We have determined the structure in two forms: D-xylose-bound enzyme and a covalent 2-deoxy-2-fluoro-alpha-D-xylosyl-enzyme intermediate complex, thus providing two snapshots in the reaction pathway. This study provides structural evidence for the proposed double displacement mechanism that involves a covalent intermediate. Furthermore, it reveals possible functional roles for His228 as the auxiliary acid/base and Glu323 as a key residue in substrate recognition.

About this StructureAbout this Structure

1UHV is a Single protein structure of sequence from Thermoanaerobacterium saccharolyticum. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of beta-D-xylosidase from Thermoanaerobacterium saccharolyticum, a family 39 glycoside hydrolase., Yang JK, Yoon HJ, Ahn HJ, Lee BI, Pedelacq JD, Liong EC, Berendzen J, Laivenieks M, Vieille C, Zeikus GJ, Vocadlo DJ, Withers SG, Suh SW, J Mol Biol. 2004 Jan 2;335(1):155-65. PMID:14659747 Page seeded by OCA on Sat May 3 11:15:05 2008

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OCA

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 [[Image:1uhv.gif|left|200px]]
- {{Structure
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+The line below this paragraph, containing "STRUCTURE_1uhv", creates the "Structure Box" on the page.
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+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=DFX:1,2-DEOXY-2-FLUORO-XYLOPYRANOSE'>DFX</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Xylan_1,4-beta-xylosidase Xylan 1,4-beta-xylosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.37 3.2.1.37] </span>
+or leave the SCENE parameter empty for the default display.
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-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1uhv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1uhv OCA], [http://www.ebi.ac.uk/pdbsum/1uhv PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1uhv RCSB]</span>
-}}
 '''Crystal structure of beta-D-xylosidase from Thermoanaerobacterium saccharolyticum, a family 39 glycoside hydrolase'''
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 [[Category: Yoon, H J.]]
 [[Category: Zeikus, G J.]]
-[[Category: covalent glycosyl-enzyme intermediate]]
+[[Category: Covalent glycosyl-enzyme intermediate]]
-[[Category: family 39 glycoside hydrolase]]
+[[Category: Family 39 glycoside hydrolase]]
-[[Category: xylan]]
+[[Category: Xylan]]
-[[Category: xylose]]
+[[Category: Xylose]]
-[[Category: xylosidase]]
+[[Category: Xylosidase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 11:15:05 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:10:30 2008''