Fig. 4

Application of tunnel engineering on other xylanases. a The relative activity of xylanase mutants. The activities of wild-type xylanases were set as control (C). b Structural comparison analysis of wild-type xylanases and the mutants. Backbone structures are shown as teal cartoon. Red sticks indicate catalytic residues. The mutated residues are shown as pink surface. The access tunnels were calculated by CAVER, named as tun_1 (blue), tun_2 (red) and tun_3 (green)