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Difference between revisions of "Carbohydrate Binding Module Family 44"
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== Structural Features == | == Structural Features == | ||
| − | + | Like many CBMs, CBM44 exhibits a typical ß-sandwich fold: two antiparallel ß-sheets form a concave and a convex surface. The concave surface forms a deep hydrophobic ligand-binding cleft that is estimated to accommodate up to five glucose residues (~24 Å) <cite>Najmudin2006</cite>. Here, three tryptophans (W189, W194 and W198) act as key residues to mediate ligand binding, as confirmed by affinity gel electrophoresis (AGE) and ITC analyses of specific mutants. The orientation of the tryptophans corresponds to the slightly twisted conformation of cello-oligosaccharides in solution. | |
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== Functionalities == | == Functionalities == | ||
Revision as of 08:25, 6 January 2023
This page is currently under construction. This means that the Responsible Curator has deemed that the page's content is not quite up to CAZypedia's standards for full public consumption. All information should be considered to be under revision and may be subject to major changes.
| CAZy DB link | |
| http://www.cazy.org/CBMnn.html |
Ligand specificities
CBM44 targets ß-1,4-polymers such as xyloglucan and cellulose (hydroxyethylcellulose and Avicel), mixed linkage ß-1,3/ß1,4- glucans (lichenan and barley) or glucomannan (konjac) [1]. Affinity for xylan was very low and binding to laminarin, curdlan, pullulan, pustulan, galactomannan or galactan was negative. Isothermal titration calorimetry (ITC) revealed highest affinity for xyloglucan as a polysaccharide, which was comparable to the affinity for cellohexaose as an oligosaccharide. For other cello-oligosaccharides, this affinity decreased with decreasing chain length, while no binding was detected for cellotriose.
Structural Features
Like many CBMs, CBM44 exhibits a typical ß-sandwich fold: two antiparallel ß-sheets form a concave and a convex surface. The concave surface forms a deep hydrophobic ligand-binding cleft that is estimated to accommodate up to five glucose residues (~24 Å) [1]. Here, three tryptophans (W189, W194 and W198) act as key residues to mediate ligand binding, as confirmed by affinity gel electrophoresis (AGE) and ITC analyses of specific mutants. The orientation of the tryptophans corresponds to the slightly twisted conformation of cello-oligosaccharides in solution.
Functionalities
Content in this section should include, in paragraph form, a description of:
- Functional role of CBM: Describe common functional roles such as targeting, disruptive, anchoring, proximity/position on substrate.
- Most Common Associated Modules: 1. Glycoside Hydrolase Activity; 2. Additional Associated Modules (other CBM, FNIII, cohesin, dockerins, expansins, etc.)
- Novel Applications: Include here if CBM has been used to modify another enzyme, or if a CBM was used to label plant/mammalian tissues? Etc.
Family Firsts
- First Identified
- Insert archetype here, possibly including very brief synopsis.
- First Structural Characterization
- Insert archetype here, possibly including very brief synopsis.