Cellulose, cellulases and cellulosomes.

The structural complexity and rigidity of cellulosic substrates have given rise to a phenomenal diversity of degradative enzymes--the cellulases. Cellulolytic microorganisms produce a wide variety of different catalytic and noncatalytic enzyme modules, which form the cellulases and act synergistically on their substrate. In some microbes, several types of cellulases are organized into an elaborate multifunctional supramolecular complex, known as the cellulosome. A combination of molecular genetic, biochemical, chemical, crystallographic and microscopic techniques are paving the way for new insights into both the structure of cellulose and the mechanisms of its hydrolysis.