Investigation of the Dynamic Mechanism of Xylanase by QENS

In this proposal we will pioneer the use of QENS in combination with molecular biology mutagenesis and in silico design to guide the re-engineering of a glycoside hydrolase, xylanase, to allow for more efficient hydrolysis of hemicellulose to xylose over a broader range of conditions. Our previous X-ray and neutron crystallography results show that a catalytic active glutamate residue has alternate conformations to transfer proton to cleave the glycosidic bond. This activity is temperature and pH dependent. However, crystallography could only give snapshot information of structure, not dynamics. Therefore we aim to study how the activity is associated with temperature and pH using QENS. This information will be used to guide in silico enzyme engineerin leading to rational mutagenesis studies in order to increase catalytic activity at higher temperature and pH.