1od3
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Carbohydrate-binding polypeptides, including carbohydrate-binding modules | + | 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== | ==About this Structure== | ||
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[[Category: Clostridium stercorarium]] | [[Category: Clostridium stercorarium]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Boraston, A | + | [[Category: Boraston, A B.]] |
| - | [[Category: Davies, G | + | [[Category: Davies, G J.]] |
| - | [[Category: Kilburn, D | + | [[Category: Kilburn, D G.]] |
[[Category: Notenboom, V.]] | [[Category: Notenboom, V.]] | ||
| - | [[Category: Rose, D | + | [[Category: Rose, D R.]] |
| - | [[Category: Warren, R | + | [[Category: Warren, R A.J.]] |
[[Category: ACY]] | [[Category: ACY]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: laminaribiose]] | [[Category: laminaribiose]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:16:13 2008'' |
Revision as of 12:16, 21 February 2008
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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 and as ligands. Known structural/functional Site: . 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
Page seeded by OCA on Thu Feb 21 14:16:13 2008
