Cloning and Molecular Characterization of β-1,3-Glucan Synthase from Sparassis crispa

Abstract

A β-glucan synthase gene was isolated from the genomic DNA of polypore mushroom Sparassis crispa, which reportedly produces unusually high amount of soluble β-1,3-glucan (β-glucan). Sequencing and subsequent open reading frame analysis of the isolated gene revealed that the gene (5,502 bp) consisted of 10 exons separated by nine introns. The predicted mRNA encoded a β-glucan synthase protein, consisting of 1,576 amino acid residues. Comparison of the predicted protein sequence with multiple fungal β-glucan synthases estimated that the isolated gene contained a complete N-terminus but was lacking approximately 70 amino acid residues in the C-terminus. Fungal β-glucan synthases are integral membrane proteins, containing the two catalytic and two transmembrane domains. The lacking C-terminal part of S. crispa β-glucan synthase was estimated to include catalytically insignificant transmembrane α-helices and loops. Sequence analysis of 101 fungal β-glucan synthases, obtained from public databases, revealed that the β-glucan synthases with various fungal origins were categorized into corresponding fungal groups in the classification system. Interestingly, mushrooms belonging to the class Agaricomycetes were found to contain two distinct types (Type I and II) of β-glucan synthases with the type-specific sequence signatures in the loop regions. S. crispa β-glucan synthase in this study belonged to Type II family, meaning Type I β-glucan synthase is expected to be discovered in S. crispa. The high productivity of soluble β-glucan was not explained but detailed biochemical studies on the catalytic loop domain in the S. crispa β-glucan synthase will provide better explanations.

Genome Survey and Transcriptome Analysis on Mycelia and Primordia of Agaricus blazei

“…e DGE profiles were also employed [55]. e construction of phylogenetic tree was implemented on http://www.phylogeny.fr/, as described by Lu et al [56].…”

β-(1→3),(1→6)-Glucans: medicinal activities, characterization, biosynthesis and new horizons

“…It is estimated that this missing includes α-helices catalytically insignificant (Yang et al 2014). Three primer pairs with degenerate bases were designed to amplify regions regarding the GLS gene from Ganoderma lucidum.…”

Biocatalytic Synthesis of Fungal β-Glucans

“…In S. cerevisiae, the most well-studied microorganism in respect to GLS molecular biology, there are two fks genes, as well as in L. edodes, Auricularia auricula-judae and P. ferulae [10], while in the strains C. albicans, C. neoformans, A. fumigatus, Ustilago maydis, P. ostreatus and P. eryngii, a single gene copy has been found [10,11,38,41,70,71]. According to a recent classification from Yang et al [72], Ascomycetes gls genes are widespread mostly in the subphylum Pezizomycotina, while for Basidiomycetes, gls genes are distributed to four subphyla, with the majority of them belonging to subphylum Agaricomycotina, class Agaricomycetes. This specific class of Basidiomycetes, including Agaricus bisporus, Trametes versicolor, S. commune and Coprinopsis cinerea, is the only class to include two different types of GLS.…”