Fig. 3

a Xylanase of Bacillus subtilis in substrate bound state with active sites and substrate binding residues, PDB (ID: 2B46). Magenta color shows the bound substrate; Gray color shows stick of active site residues. Gating residues also observed in the binding pocket. b 3-D model of predicted xylanase structure of Bacillus amyloliquefaciens obtained from I-TASSER and used for the selection of gating residues. The structure was analyzed in PyMOL, Benzene rings show the line structures of aromatic amino acids. Orange color shows targeted amino acids for the single mutations (W63, Y128, W144, Y124 and W187), Red color displays active site residues (E137 and E226)