The nature of the carbohydrate binding module determines the catalytic efficiency of xylanase Z of Clostridium thermocellum.

Highlights: [•] Variants of xynlanase Z of Clostridium thermocellum in combination with CBM6 and CBM22 were expressed in E. coli. [•] The construct with CBM22 showed 5-fold higher activity as compared to the one containing CBM6. [•] Location of the binding site inside a tunnel like structure of the CBM6 construct seemed to restrict the substrate binding. [•] The construct with CBM22 produced a more open structure, facilitating substrate binding and release of the product. [ABSTRACT FROM AUTHOR]