MOLECULAR-CLONING, SEQUENCE-ANALYSIS AND EXPRESSION OF THE GENE ENCODING AN ANTIFUNGAL-PROTEIN FROM ASPERGILLUS-GIGANTEUS

The gene encoding the precursor of a small secretory protein with anti fungal activity was isolated from A. giganteus and characterized by re striction, mapping, hybridization and nucleotide sequencing. The promo ter contains a typical TATA-box at a distance of 135 bp upstream of th e open reading frame. The open reading frame is interrupted by two sma ll introns with conserved splice sites. The precursor of the antifunga l protein (AFP) consists of 94 amino acids and appears to be processed to the mature AFP of 51 amino acids by a two-step process. Transfer o f the gene into A. niger yielded only transformants with a very low ex pression level, probably because high-expression transformants were co unterselected by the antifungal activity of the recombinant protein.