Analysis of a polygalacturonase gene ofUstilago maydisand characterization of the encoded enzyme

摘要: Ustilago maydis is a pathogenic fungus that produces the corn smut. It biotrophic parasite depends on living plant tissues for its proliferation and development. Polygalacturonases are secreted by pathogens to solubilize cell-wall required pathogen virulence. In this paper, we report isolation of U. polygalacturonase gene (Pgu1) functional structural characterization encoded enzyme. The Pgu1 expressed when grown in liquid culture media containing different carbon sources. tissue, expression increased as function incubation time. was detected during infection around 10 days post-infection with FB-D12 strain combination teliospore formation. Synthesis secretion active recombinant PGU1 were achieved using Pichia pastoris, purified enzyme had optimum temperature 34 °C, pH 4.5, Km 57.84 g/L polygalacturonic acid, Vmax 28.9 µg/min mg. Structural models based homologous enzymes yielded typical right-handed β-helix fold pectinolytic classified glycosyl hydrolases family 28, related endo rather than exo polygalacturonases.