Figure 5.

Cellular model of cellulose degradome in Clostridium cellulolyticum. The cell employs CCR (A) to sense intracellular level of glycolytic intermediates and controls the core cellulose-degrading machinery that mainly includes cellulosomal components (B). On the other hand, TCS systems (C) sense extracellular soluble sugars and respectively regulate carbon-substrate specific CAZymes (D) and transporters (E). Due to the synergy of cellulosomal enzymes and the substrate-specific CAZymes, cellulose is degraded efficiently and the resulted soluble di- and mono-saccharides transported into cell.