Effects of substrate binding site residue substitutions of xynA from Bacillus amyloliquefaciens on substrate specificity.

ABSTRACT:

Background

The aromatic residues of xylanase enzyme, W187, Y124, W144, Y128 and W63 of substrate binding pocket from Bacillus amyloliquefaciens were investigated for their role in substrate binding by homology modelling and sequence analysis. These residues are highly conserved and play an important role in substrate binding through steric hindrance. The substitution of these residues with alanine allows the enzyme to accommodate nonspecific substrates.

Results

Wild type and mutated genes were cloned and overexpressed in BL21. Optimum pH and temperature of rBAxn exhibited pH 9.0 and 50 °C respectively and it was stable up to 215 h. Along with the physical properties of rBAxn, kinetic parameters (K_m 19.34 ± 0.72 mg/ml; k_cat 6449.12 ± 155.37 min^- 1</

SUBMITTER: Prajapati AS 

PROVIDER: S-EPMC5812043 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature