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Glycoside hydrolases of family 138 exhibit α-D-galacturonidase activity. This is based on data from the characterisation of the founding member of the family BT0997 encoded by the human gut bacterium B. thetaiotaomicron [1]. BT0997 hydrolyses a fragment (GalA-α1,2(GalA-β1,3)(2MeXyl-α1,3-Fuc-α1,4)Rha-α1,3-Api) of chain A from the pectic polysaccharide rhamnogalacturonan II, producing D-galacturonic acid and the resulting oligosaccharide GalA-β1,3(2MeXyl-α1,3Fuc-α1,4)Rha-α1,3Api [1]. Several members of this family have been identified in gut and environmental bacteria with a majority of the encoding microbes belonging to the Bacteroidetes phylum [2, 3]. This phylum is highly represented in human gut microbial populations [4].
Kinetics and Mechanism
The kinetic mechanism for this family has not been reported.
Catalytic Residues
The catalytic residues for this family have not yet been identified.
Three-dimensional structures
No 3D structure for a member of this family has been currently reported.
