2XOM

Atomic resolution structure of TmCBM61 in complex with beta-1,4- galactotriose

Summary for 2XOM

• Entry DOI: 10.2210/pdb2xom/pdb
• Related: 2XON
• Related PRD ID: PRD_900114
• Descriptor: ARABINOGALACTAN ENDO-1,4-BETA-GALACTOSIDASE, beta-D-galactopyranose-(1-4)-beta-D-galactopyranose-(1-4)-beta-D-galactopyranose, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: hydrolase, galactan, carbohydrate-binding module, glycoside hydrolase, beta-sandwich.
• Biological source: THERMOTOGA MARITIMA
• Total number of polymer chains: 1
• Total formula weight: 17762.61

Authors

Cid, M.,Lodberg-Pedersen, H.,Kaneko, S.,Coutinho, P.M.,Henrissat, B.,Willats, W.G.T.,Boraston, A.B. (deposition date: 2010-08-20, release date: 2010-09-08, Last modification date: 2024-05-08)

Primary citation

Cid, M.,Pedersen, H.L.,Kaneko, S.,Coutinho, P.M.,Henrissat, B.,Willats, W.G.T.,Boraston, A.B.
Recognition of the Helical Structure of Beta-1,4-Galactan by a New Family of Carbohydrate-Binding Modules.
J.Biol.Chem., 285:35999-, 2010

PubMed Abstract: The microbial enzymes that depolymerize plant cell wall polysaccharides, ultimately promoting energy liberation and carbon recycling, are typically complex in their modularity and often contain carbohydrate-binding modules (CBMs). Here, through analysis of an unknown module from a Thermotoga maritima endo-β-1,4-galactanase, we identify a new family of CBMs that are most frequently found appended to proteins with β-1,4-galactanase activity. Polysaccharide microarray screening, immunofluorescence microscopy, and biochemical analysis of the isolated module demonstrate the specificity of the module, here called TmCBM61, for β-1,4-linked galactose-containing ligands, making it the founding member of family CBM61. The ultra-high resolution X-ray crystal structures of TmCBM61 (0.95 and 1.4 Å resolution) in complex with β-1,4-galactotriose reveal the molecular basis of the specificity of the CBM for β-1,4-galactan. Analysis of these structures provides insight into the recognition of an unexpected helical galactan conformation through a mode of binding that resembles the recognition of starch.

PubMed: 20826814
DOI: 10.1074/JBC.M110.166330

Experimental method

X-RAY DIFFRACTION (0.95 Å)