2004年10月
Crystal structure of a family 54 alpha-L-arabinofuranosidase reveals a novel carbohydrate-binding module that can bind arabinose
JOURNAL OF BIOLOGICAL CHEMISTRY
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- 巻
- 279
- 号
- 43
- 開始ページ
- 44907
- 終了ページ
- 44914
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1074/jbc.M405390200
- 出版者・発行元
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
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.
- リンク情報
- ID情報
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- DOI : 10.1074/jbc.M405390200
- ISSN : 0021-9258
- Web of Science ID : WOS:000224505600081