The first crystal structure of a family 31 carbohydrate-binding module with affinity to β-1,3-xylan

• Published in: FEBS letters Vol. 579; no. 20; pp. 4324 - 4328
• Main Authors: Hashimoto, Hiroshi, Tamai, Youichi, Okazaki, Fumiyoshi, Tamaru, Yutaka, Shimizu, Toshiyuki, Araki, Toshiyoshi, Sato, Mamoru
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.08.2005
• Subjects: Alcaligenes - enzymology; Amino Acid Sequence; Carbohydrate Metabolism; Carbohydrate-binding module; CBM; Crystal structure; Crystallography, X-Ray; Family 31; Immunoglobulin fold; Molecular Sequence Data; Protein Conformation; Protein Folding; Xylan Endo-1,3-beta-Xylosidase - chemistry; Xylan Endo-1,3-beta-Xylosidase - metabolism; Xylans - metabolism; β-1,3-Xylan; Carbohydrate-binding module; β-1,3-Xylan; CBM; Crystal structure; Family 31; Immunoglobulin fold
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2005.06.062

Here, we present the crystal structure of the family 31 carbohydrate-binding module (CBM) of β-1,3-xylanase from Alcaligenes sp. strain XY-234 (AlcCBM31) determined at a resolution of 1.25Å. The AlcCBM31 shows affinity with only β-1,3-xylan. The AlcCBM31 molecule makes a β-sandwich structure composed of eight β-strands with a typical immunoglobulin fold and contains two intra-molecular disulfide bonds. The folding topology of AlcCBM31 differs from that of the large majority of other CBMs, in which eight β-strands comprise a β-sandwich structure with a typical jelly-roll fold. AlcCBM31 shows structural similarity with CBM structures of family 34 and family 9, which also adopt structures based on immunoglobulin folds.