2J72

alpha-glucan recognition by a family 41 carbohydrate-binding module from Thermotoga maritima pullulanase PulA

Summary for 2J72

• Entry DOI: 10.2210/pdb2j72/pdb
• Related: 2J71 2J73
• Related PRD ID: PRD_900010
• Descriptor: PULLULANASE, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: carbohydrate-binding module, hydrolase, glycosidase, maltotetraose, beta- sandwich fold, alpha-glucan binding
• Biological source: THERMOTOGA MARITIMA
• Total number of polymer chains: 2
• Total formula weight: 25488.58

Authors

Lammerts van Bueren, A.,Boraston, A.B. (deposition date: 2006-10-05, release date: 2006-10-17, Last modification date: 2023-12-13)

Primary citation

Lammerts Van Bueren, A.,Boraston, A.B.
The Structural Basis of Alpha-Glucan Recognition by a Family 41 Carbohydrate-Binding Module from Thermotoga Maritima
J.Mol.Biol., 365:555-, 2007

PubMed Abstract: Starch recognition by carbohydrate-binding modules (CBMs) is important for the activity of starch-degrading enzymes. The N-terminal family 41 CBM, TmCBM41 (from pullulanase PulA secreted by Thermotoga maritima) was shown to have alpha-glucan binding activity with specificity for alpha-1,4-glucans but was able to tolerate the alpha-1,6-linkages found roughly every three or four glucose units in pullulan. Using X-ray crystallography, the structures were solved for TmCBM41 in an uncomplexed form and in complex with maltotetraose and 6(3)-alpha-D-glucosyl-maltotriose (GM3). Ligand binding was facilitated by stacking interactions between the alpha-faces of the glucose residues and two tryptophan side-chains in the two main subsites of the carbohydrate-binding site. Overall, this mode of starch binding is quite well conserved by other starch-binding modules. The structure in complex with GM3 revealed a third binding subsite with the flexibility to accommodate an alpha-1,4- or an alpha-1,6-linked glucose.

PubMed: 17095014
DOI: 10.1016/J.JMB.2006.10.018

Experimental method

X-RAY DIFFRACTION (1.49 Å)