This page has been approved by the Responsible Curator as essentially complete. CAZypedia is a living document, so further improvement of this page is still possible. If you would like to suggest an addition or correction, please contact the page's Responsible Curator directly by e-mail.
CBM76 is a small family containing only five members found exclusively in Ruminococci. The founding member of this family is CBM76RfGH44 from Ruminococcus flavefaciens that recognizes different β-1,4-glucans [1]. By isothermal titration calorimetry, the affinity of this binding module to xyloglucan (KA 1.1 x 106 M-1) is 100-fold higher than to glucomannan, barley β-glucan, hydroxyethylcellulose and XXXG (the repeating unit of xyloglucan, where X comprises glucose decorated at O6 with xylose and G corresponds to undecorated glucose) [1].
Structural Features
No three-dimensional structure has been solved for this CBM family.
Functionalities
The founding member of this family, CBM76RfGH44, is appended to a glycoside hydrolase family 44 (GH44) and a C-terminal dockerin. The carbohydrate-binding module specificity for β-1,4-glucans is consistent with the previously reported activity for GH44 enzymes (endoglucanase or xyloglucanase) [1]; however, the impact of CBM76RfGH44 binding module on GH44 substrate recognition and catalysis it is not known.
