Three-Dimensional Structure of Cellobiohydrolase II fromTrichoderma reesei

The enzymatic degradation of cellulose is an important process, both ecologically and commercially. The three-dimensional structure of a cellulase, the enzymatic core of CBHII from the fungus Trichoderma reesei reveals an α-β protein with a fold similar to but different from the widely occurring barrel topology first observed in triose phosphate isomerase. The active site of CBHII is located at the carboxyl-terminal end of a parallel β barrel, in an enclosed tunnel through which the cellulose threads. Two aspartic acid residues, located in the center of the tunnel are the probable catalytic residues.