<i>In-Silico</i> Characterization and Mutagenesis of β-Glucosidase from <i>Anoxybacillus</i> sp. SK3-4

Abstract

Structural analysis of β-glucosidase (Bgl; EC 3.2.1.21) isolated from Anoxibacillus sp SK3-4 were carried out with the aim of generating structural and functional information of the protein, as well as theoretically improve thermo-stability by in silico mutagenesis. Different bioinformatics databases, software’s and servers were used to generate both functional and structural information and results of the primary sequence analysis revealed that the protein has 455 amino acid residues with molecular weight of 52627.8 Da. Pattern and profile search using Interpro indicate the presence of β-glucosidase hydrolase catalytic domain. Biochemical function of the enzyme proved it catalyses the hydrolysis of 6-phospho-beta-D-glucosyl-(1, 4)-glucose, it also catalyze the hydrolysis of several phospho-beta-D-glucosides but not phosphorylated form. Tertiary structure modelling and subsequent validation of the models have identified CPH model as the best model compared to those built by Swiss and I-TASSER. Predicted active site residues were Thy (166) and Arg (355). Other Important residues forming the binding site were predicted to include Gln (23), His (120), Asn (165), Tyr (298), Trp (402) and Ser (410). Site directed mutagenesis was adopted to introduce the mutation at two sites: Arg (41) Lys and Lys (45) Glu, which improve the thermostabilty of the protein.