In silico structural and dynamic stability analysis of an endo-1,4-β-xylanase from Agrobacterium sp. strain DKPNP3, isolated from the gut of Gonocephalum sp.

Xylanases are one of the most important hydrolytic enzymes involved in plant hemicellulose degradation with potential industrial as well as ecological significance. This study presents a comprehensive characterization of an endo-1,4-β-xylanase enzyme from Agrobacterium sp. Strain DKPNP3 isolated from the beetle gut of Gonocephalum sp. (Coleoptera: Tenebrionidae). Bioinformatics analyses were performed, including physicochemical characterization, phylogenetic assessment, conserved domain identification, secondary and tertiary structure prediction, subcellular localization prediction, homology modeling, structural validation, molecular docking and molecular dynamics simulation to assess the stability of this protein. The enzyme belongs to the glycoside hydrolase family 10 (GH10) with 339 amino acids, molecular weight of 37.8 kDa, and acidic in nature (pi 5.8). The homology model demonstrated high structural reliability, with an ERRAT score of 96.364% and a QMEAN Z-score of 0.59. Molecular dynamics simulations demonstrated that the enzyme is structurally stable in both its apo and ligand-bound forms. The apo form showed stability comparable to a well-characterized synthetic construct xylanase from Bacillus halodurans (GenBank accession number: MW311490), which was used as a positive control. Furthermore, simulations performed at multiple temperatures indicated retention of conformational integrity under different thermal conditions, suggesting potential thermostability. The intracellular nature of the enzyme, as predicted by in silico analysis, was confirmed by experimental validation using Congo Red-xylan agar assay and quantification with di nitro salicylic acid (DNSA).