Fig. 3

Interaction between residues in loop 8 and the substrate. a The hydrogen bonding network between wild-type TfCel5A and the substrate at the − 3 and − 2 subsites. b Measurements of the catalytic activity relative to WT TfCel5A and substrate binding affinity of the loop 8 mutants. DARA and KDRE represent double mutants D394A_R396A and D394K_R396E, respectively. c–h The hydrogen bonding interactions of loop 8 and the substrate revealed by the MD simulations of the mutants