Characterization and expression of β-1,3-Glucanase gene (GlGH128A) in Ganoderma lucidum

We identified a putative β-1,3-glucanase gene (GlGH128A) classified into the glycoside hydrolase family (GH) 128 from Ganoderma lucidum. This gene consists of a total length of 816 bp including the start and stop codon, and encode 271 amino acids, including a 22-residue signal peptide. The predicted mature protein has a molecular mass of 27.5 kDa and an isoelectric point of 5.82. Amino acid sequence comparison between GlGH128A and GH-128 β-1,3-glucanase from Lentinula edodes (LeGLU1), and homology model of GlGH128A based on LeGLU1 crystal structure exhibits TIM barrel fold with conserved two catalytic glutamic acid residues, and suggested two disulfide bonds of GlGH128A. Expression analysis showed that GlGH128A is expressed at higher levels in the fruiting body after harvest across multiple strains. These findings suggest that GlGH128A contributes to the autolysis of G. lucidum fruiting bodies.