X-ray computed microtomography as a possible complementary approach to investigate synergism within multimodular glycoside hydrolases
Résumé
In Nature, the plant-based organic carbon contained within plant cell walls is mainly recycled by the action of cellulolytic microorganisms, such as bacteria and fungi, which produce complex arrays of cell wall-degrading enzymes. Many of the enzymes that degrade plant cell wall polysaccharides are modular proteins, which contain single or multiple copies of both catalytic domain(s) and CBM(s). Cellulolytic microorganisms developed a couple of strategies to break down the complex plant cell wall; secrete free enzymes into their surroundings or produce large multi-component cell-bound structures, which harbour several enzymes displaying complementary activities. In bothcase, substrate is attacked by different enzymes acting together at different regions, and much more than sum of individual different enzymatic activities, synergism drives the efficiency of such system. Nevertheless, this complex process is still not completely understood. Despite an abundant literature about the role of CBM as an enhancer ofthe catalytic activity, we miss information about relationship between enzymes, CBMs and modularity in planta.