Effects of the Outer-Cleft Aromatic Ring Deletion on the Resistivity of a GH11 Xylanase to the Lignin-Like Monolignol Aggregates

Abstract The effects of outer-cleft aromatic ring mutations Y5A and F124A on the resistivity of a GH11 xylanase (xyn11A) from Bacillus Firmus K1 to the inhibition by highly-concentrated coniferyl alcohols were investigated both in vitro and an in silico, in which coniferyl alcohols tended to aggregate into clusters and induced the inhibition. The mutants displayed a lower inhibition percentage despite the decrease in enzymatic activities due to the mutation-induced conformational changes of xyn11A. The mutants' ability to resist coniferyl alcohols could be explained by the disruption of the coniferyl clusters formed within the binding cleft due to aromatic ring deletions.