Difference between revisions of "Carbohydrate Binding Module Family 75"

Revision as of 07:33, 23 May 2018

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.

Author: ^^^Ana Luis^^^
Responsible Curator: ^^^Harry Gilbert^^^

CAZy DB link
https://www.cazy.org/CBM75.html

Ligand specificities

CBM75 is a small bacterial family containing only 3 members comprising around 290 amino acids and found exclusively in Ruminococci. The only family member characterized is CBM75_RfGH43 from Ruminococcus flavefaciens that specifically binds to xyloglucan [1]. By isothermal titration calorimetry, the affinity to xyloglucan repeating unit XXXG (X comprises glucose decorated at O6 with xylose and G corresponds to undecorated glucose) is similar to the polysaccharide, suggesting that CBM75_RfGH43 has four binding sites that recognize the backbone glucose units. However, the specific binding to xyloglucan and not to other β-glucan polysaccharides indicates that at least some of the xylose side chains also have a major contribution to ligand recognition [1].

Structural Features

No three-dimensional structure has been solved for this CBM family.

Functionalities

Ruminococcus flavefaciens CBM75_RfGH43, is a biding module of a protein containing a glycoside hydrolase family 43 (GH43) and a C-terminal dockerin module [1]. The GH43 catalytic domain, is a member of subfamily 16 (GH43_16) that is populated only with arabinofuranosidases [2]. Indeed, the catalytic module RfGH43 is active against 4-nitrophenyl-α-L-arabinofuranose but does not cleave arabinoxylans and arabinans, suggesting that this enzyme may target arabinofuranose residues that decorate other polysaccharides [1]. The CBMs specificity is consistent with the activity of the appended enzyme. Since CBM75_RfGH43 binds specifically to xyloglucan it was suggested that the enzyme GH43_16 may target arabinofuranose decorations present on xyloglucan from tomato [1].

Family Firsts

First Identified: CBM75_RfGH43 from Ruminococcus flavefaciens [1].
First Structural Characterization: No three-dimensional structure has been solved for this family.

References

All Medline abstracts: PubMed

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 == Ligand specificities ==
-CBM75 is a small bacterial family containing only 3 members comprising around 290 amino acids and found exclusively in ''Ruminococci''. The only family member characterized is CBM75<sub>RfGH43</sub> from ''Ruminococcus flavefaciens'' that specifically binds to xyloglucan <cite>Venditto2016</cite>. By isothermal titration calorimetry, the affinity to xyloglucan repeating unit XXXG (X comprises glucose decorated at O6 with xylose and G corresponds to undecorated glucose) is similar to the polysaccharide, suggesting that CBM75<sub>RfGH43</sub> has four binding sites that recognize the backbone glucose units. However, the specific binding to xyloglucan and not to other β-glucan polysaccharides indicates that at least some of the xylose side chains also have a major contribution to ligand recognition <cite>Venditto2016</cite>.
+CBM75 is a small bacterial family containing only 3 members comprising around 290 amino acids and found exclusively in Ruminococci. The only family member characterized is CBM75<sub>RfGH43</sub> from ''Ruminococcus flavefaciens'' that specifically binds to xyloglucan <cite>Venditto2016</cite>. By isothermal titration calorimetry, the affinity to xyloglucan repeating unit XXXG (X comprises glucose decorated at O6 with xylose and G corresponds to undecorated glucose) is similar to the polysaccharide, suggesting that CBM75<sub>RfGH43</sub> has four binding sites that recognize the backbone glucose units. However, the specific binding to xyloglucan and not to other β-glucan polysaccharides indicates that at least some of the xylose side chains also have a major contribution to ligand recognition <cite>Venditto2016</cite>.
 == Structural Features ==