Substrate molecule enhances the thermostability of a mutant of a family 11 xylanase from Neocallimastix patriciarum

Abstract

Thermophilic xylanases are ideal for many industrial processes operated at elevated temperatures. Here, we report a mutant of a family 11 xylanase (Xyn-CDBFV) from Neocallimastix patriciarum with a mutation (D57N) in the active center could be further stabilized by the substrate. Despite that the
thermostability of the two enzymes are almost the same in the absence of the substrate, the mutant displays a 10 - 15oC higher optimal temperature of activity than the wild type. Potential hydrogen bonding interactions predicted by molecular docking between the substrate molecule and residues
N57, E202 of the mutant are probably responsible for the stabilizing effect. This suggests that it will be useful to consider the stabilizing effect induced by the substrate in optimization processes of enzyme thermostability.