Figure 3.

Structural disorder of linker regions in processive enzymes. The linker region in monomeric processive enzymes tends to be highly disordered, as shown here for three illustrative examples by the IUPred algorithm [41]. Traces of disorder score are given for the human and matrix metalloproteinase-9 (MMP-9) sequence (A), bacterial cellulase 6A (B) and Ribonuclease H1 (RNAseH1) (C). In each case, the sharp transition from order to disorder (IUPred score > 0.5) and again to order clearly delimits the linker as a disordered element connecting two globular domains. Globular domains are visualized on top of the diagrams, with blue rectangles representing binding domains and red ones representing catalytic domains.