1od3
From Proteopedia
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STRUCTURE OF CSCBM6-3 FROM CLOSTRIDIUM STERCORARIUM IN COMPLEX WITH LAMINARIBIOSE
Overview
Carbohydrate-binding polypeptides, including carbohydrate-binding modules, (CBMs) from polysaccharidases, and lectins, are widespread in nature., Whilst CBMs are classically considered distinct from lectins, in that they, are found appended to polysaccharide-degrading enzymes, this distinction, is blurring. The crystal structure of CsCBM6-3, a "sequence-family 6" CBM, in a xylanase from Clostridium stercorarium, at 2.3 A reveals a similar, all beta-sheet fold to that from MvX56, a module found in a family 33, glycoside hydrolase sialidase from Micromonospora viridifaciens, and the, lectin AAA from Anguilla anguilla. Sequence analysis leads to the, classification of MvX56 and AAA into a family distinct from that, containing CsCBM6-3. Whilst these polypeptides are similar in structure, they have quite different carbohydrate-binding specificities. AAA is known, to bind fucose; CsCBM6-3 binds cellulose, xylan and other beta-glucans., Here we demonstrate that MvX56 binds galactose, lactose and sialic acid., Crystal structures of CsCBM6-3 in complex with xylotriose, cellobiose, and, laminaribiose, 2.0 A, 1.35 A, and 1.0 A resolution, respectively, reveal, that the binding site of CsCBM6-3 resides on the same polypeptide face as, for MvX56 and AAA. Subtle differences in the ligand-binding surface give, rise to the different specificities and biological activities, further, blurring the distinction between classical lectins and CBMs.
About this Structure
1OD3 is a Single protein structure of sequence from Clostridium stercorarium with CA and ACY as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Structure and ligand binding of carbohydrate-binding module CsCBM6-3 reveals similarities with fucose-specific lectins and "galactose-binding" domains., Boraston AB, Notenboom V, Warren RA, Kilburn DG, Rose DR, Davies G, J Mol Biol. 2003 Mar 28;327(3):659-69. PMID:12634060
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