Some Inverting Glycosidase Families

The endoglucanases, however, act on amorphous regions of cellulose and have clefts, rather than tunnels, as active sites. It is possible in Family 6 to convert a cellobiohydrolase to an endoglucanase by deleting the loop of protein which forms the roof of the active site tunnel, by site-directed mutagenesis. 

3 GH 9. Further clues that the machinery for activation of the nucleophilic water in inverting enzymes may not be that critical come from an endocellulase from Clostridium stercorarum, which lost activity against crystalline cellulose, but not soluble oligosaccharides, on mutation of the presumed catalytic base.  

4 GH 14. The main members of this family are p-amylases, which yield p-maltose from the non-reducing ends of starch. Four maltose molecules are found in the complex of maltose with the holoenzyme from Bacillus cereus, two in tandem in the active site, one in a C-terminal CBM and a fourth in what appears to be an internal CBM.  

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