1wd3
From Proteopedia
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Crystal structure of arabinofuranosidase
Overview
As the first known structures of a glycoside hydrolase family 54 (GH54), enzyme, we determined the crystal structures of free and arabinose-complex, forms of Aspergillus kawachii IFO4308 alpha-l-arabinofuranosidase, (AkAbfB). AkAbfB comprises two domains: a catalytic domain and an, arabinose-binding domain (ABD). The catalytic domain has a beta-sandwich, fold similar to those of clan-B glycoside hydrolases. ABD has a, beta-trefoil fold similar to that of carbohydrate-binding module (CBM), family 13. However, ABD shows a number of characteristics distinctive from, those of CBM family 13, suggesting that it could be classified into a new, CBM family. In the arabinose-complex structure, one of three, arabinofuranose molecules is bound to the catalytic domain through many, interactions. Interestingly, a disulfide bond formed between two adjacent, cysteine residues recognized the arabinofuranose molecule in the active, site. From the location of this arabinofuranose and the results of a, mutational study, the nucleophile and acid/base residues were determined, to be Glu(221) and Asp(297), respectively. The other two arabinofuranose, molecules are bound to ABD. The O-1 atoms of the two arabinofuranose, molecules bound at ABD are both pointed toward the solvent, indicating, that these sites can both accommodate an arabinofuranose side-chain moiety, linked to decorated arabinoxylans.
About this Structure
1WD3 is a Single protein structure of sequence from Aspergillus kawachii. Active as Alpha-N-arabinofuranosidase, with EC number 3.2.1.55 Full crystallographic information is available from OCA.
Reference
Crystal structure of a family 54 alpha-L-arabinofuranosidase reveals a novel carbohydrate-binding module that can bind arabinose., Miyanaga A, Koseki T, Matsuzawa H, Wakagi T, Shoun H, Fushinobu S, J Biol Chem. 2004 Oct 22;279(43):44907-14. Epub 2004 Aug 3. PMID:15292273
Page seeded by OCA on Sat Nov 24 23:45:31 2007
