THE CELLULOLYTIC SYSTEM OF STREPTOMYCES-RETICULI

The bacterium Streptomyces reticuli produces an unusual mycelia-associ ated cellulase (Avicelase, Cel1) which is solely sufficient to degrade crystalline cellulose to cellobiose. The enzyme consists of a binding domain, one adjoining region with unknown function, and a catalytic d omain belonging to the cellulase family E. During cultivation, the str ain produces a specific protease which processes the Avicelase to a tr uncated enzyme sacking the binding domain. The cellulase synthesis is regulated by induction (Avicel) and repression (metabolizable sugars a nd glycerol).