Demonstration of the importance for cellulose hydrolysis of CelS, the most abundant cellulosomal cellulase in Chlostridium thermocellum

摘要

Anaerobic and aerobic bacteria use different mechanisms to de-grade cellulose, with many aer-obic microorganisms secreting a synergistic set of individual enzymes that includes multiple cellulases, most of which contain a carbohydrate-binding module (CBM) in addition to their catalytic do-main (free enzyme mechanism). Anaero-bic microorganisms usually produce a similar set of enzymes, but they are pres-ent in large multienzyme complexes (>1 million molecular weight) called cellulo-somes (cellulosomal mechanism) (1). Most of the cellulosomal enzymes do not contain a CBM, but the scaffoldin protein in the cellulosome does contain a CBM.