Figure 3

Schematic depiction of the putative behavior of CelA on cellulose. The GH48 catalytic domain primarily degrades crystalline cellulose (straight line); whereas the GH9 degrades amorphous regions (jagged line) and processively creates nicks in the crystalline regions for the GH48 catalytic domain to engage. As long as the CBMs are actively bound to the substrate, CelA will produce cavities because the length of the linker peptide limits the separation of the catalytic domains.