Analysis of Keystone Enzyme in Agar Hydrolysis Provides Insight into the Degradation of a Polysaccharide from Red Seaweeds

Background: The catalytic mechanism and substrate recognition required for cleavage of the -linkage in agarose are unclear.
Results: Structural analysis of a family 117 glycoside hydrolase details substrate recognition and supports an inverting mechanism. 

Conclusion: GH117 enzymes use substrate distortion and an unusual general acid for catalysis.
Significance: Microbes may utilize alternate strategies to catalyze the degradation of polysaccharides with unique structural characteristics