Gene structural analysis and functional prediction of chi protein produced by the bacterium stenotrophomonas maltophilia

Abstract

Molecular characterization of genes is a tool used to understand gene function. Chitin is the most abundant nitrogenous organic compound in nature; it is basically inert, but it can be transformed by the action of chitinases to several derivatives, which are of great interest in various areas of industry. These enzymes are widely distributed in many organisms and can be potentially used in genetic engineering to add characteristics that increase its activity. We examined 10 chitenase genes from 10 different strains of Stenotrophomonas maltophilia native to Chiapas, Mexico that have different enzymatic activities. After sequencing of the gene, a bioinformatic analysis was performed, which revealed an average length of 2100 bp and 64.7% G+C content of the genes. The open reading frame consists of 699 amino acids, which corresponds to an average molecular mass of 72.4 kDa, and an isoelectric point of 6.66. The genes exhibited between 99.3 and 100% identity. Additionally, the 3D structure of the chitinolytic enzyme was predicted using the structure of a chitinase from Streptomyces thermoviolaceus as a template. Results suggested that the chitinase of S. maltophilia contains four characteristic domains of these enzymes, the Chia1_BD, Big_3_5, type III fibronectin (FN3), and GH18 domains. This study provides basic knowledge for enzyme design using genetic engineering.