A novel endo-beta-1,3-glucanase, BGN13.1, involved in the mycoparasitism of Trichoderma harzianum.
The mycoparasitic fungus Trichoderma harzianum CECT 2413 produces at least three extracellular beta-1,3-glucanases. The most basic of these extracellular enzymes, named BGN13.1, was expressed when either fungal cell wall polymers or autoclaved mycelia from different fungi were used as the carbon source. BGN13.1 was purified to electrophoretic homogeneity and was biochemically characterized. The enzyme was specific for beta-1,3 linkages and has an endolytic mode of action. A synthetic oligonucleotide primer based on the sequence of an internal peptide was designed to clone the cDNA corresponding to BGN13.1. The deduced amino acid sequence predicted a molecular mass of 78 kDa for the mature protein. Analysis of the amino acid sequence indicates that the enzyme contains three regions, one N-terminal leader sequence; another, nondefined sequence; and one cysteine-rich C-terminal sequence. Sequence comparison shows that this beta-1,3-glucanase, first described for filamentous fungi, belongs to a family different from that of its previously described bacterial, yeast, and plant counterparts. Enzymatic-activity, protein, and mRNA data indicated that bgn13.1 is repressed by glucose and induced by either fungal cell wall polymers or autoclaved yeast cells and mycelia. Finally, experimental evidence showed that the enzyme hydrolyzes yeast and fungal cell walls.
de la Cruz
J
J
Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Cientificas y Universidad de Sevilla, Spain.
Pintor-Toro
J A
JA
Benítez
T
T
Llobell
A
A
Romero
L C
LC
D000595:Amino Acid Sequence; D000898:Antibiosis; D001483:Base Sequence; D015152:Blotting, Northern; D002473:Cell Wall / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D005658:Fungi / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
D018076:DNA, Complementary; D005656:Fungal Proteins; D004693:Glucan Endo-1,3-beta-D-Glucosidase