NUCLEOTIDE-SEQUENCE OF A BETA-1,3-GLUCANASE ISOENZYME IIA GENE OF OERSKOVIA-XANTHINEOLYTICA LL-G109 (CELLULOMONAS-CELLULANS) AND INITIAL CHARACTERIZATION OF THE RECOMBINANT ENZYME EXPRESSED IN BACILLUS-SUBTILIS

The nucleotide sequence of the beta glII(A) gene, encoding the extrace llular beta-1,3-glucanase IIA (beta glII(A)) of the yeast-lytic actino mycete Oerskovia xanthineolytica LL G109, was determined, Sequence com parison shows that the beta glII(A) enzyme has over 80% identity to th e beta glII isoenzyme, an endo-beta-1,3-glucanase having low yeast-lyt ic activity secreted by the same bacterium. The beta glII(A) enzyme la cks a glucan- or mannan-binding domain, such as those observed in beta -1,3-glucanases and proteases having high yeast/fungus-lytic activity. It can be included in the glycosyl hydrolase family 16. Gene fusion e xpression in Bacillus subtilis DN1885 followed by preliminary characte rization of the recombinant gene product indicates that beta glII(A) h as a pI of 3.8 to 4.0 and is active on both laminarin and curdlan, hav ing an acid optimum pH activity (ca. 4.0).