Premium
Essential role of a family‐32 carbohydrate‐binding module in substrate recognition by Clostridium thermocellum mannanase Ct Man5A
Author(s) -
Mizutani Kimiya,
Sakka Makiko,
Kimura Tetsuya,
Sakka Kazuo
Publication year - 2014
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2014.03.022
Subject(s) - carbohydrate binding module , clostridium thermocellum , substrate (aquarium) , glycoside hydrolase , biochemistry , isothermal titration calorimetry , chemistry , binding site , stereochemistry , biology , enzyme , cellulase , ecology
The family‐5 glycoside hydrolase domain (GH5) and the family‐32 carbohydrate‐binding module (CBM32) of Clostridium thermocellum mannanase Ct Man5A, along with their genetically inactivated derivatives, were collectively or separately expressed. Their catalytic and substrate‐binding abilities were measured to investigate importance of CBM32 in substrate recognition by Ct Man5A. Characterization of the truncated derivatives of Ct Man5A and isothermal calorimetry analysis of the interaction between the inactivated proteins and mannooligosaccharides suggested that GH5 and CBM32 collectively formed a substrate‐binding site capable of accommodating a mannotetraose unit in Ct Man5A. This suggested that CBM32 directly participated in the substrate recognition required for catalytic action.