Comparison of the domain-level organization of starch hydrolases and related enzymes.

Structure-prediction and hydrophobic-cluster analysis of several starch hydrolases and related enzymes indicated the organization of eleven domain types. Most enzymes possess a catalytic (beta/alpha)8-barrel and a smaller C-terminal domain as seen in crystal structures of alpha-amylase and cyclodextrin glucanotransferase. Some also have a starch-granule-binding domain. Enzymes breaking or forming endo-alpha-1,6 linkages contain domains N-terminal to the (beta/alpha)8-barrel.