X-ray crystallographic studies of family 11 xylanase Michaelis and product complexes: implications for the catalytic mechanism

X-ray structures of a family 11 xylanase with bound xylohexaose substrate or products revealed six sugar-binding subsites in the active site of the enzyme. Replacing amino acids near the catalytic glutamic acid 177 decreased the xylanase activity but increased the relative activity at alkaline pH.