Cloning of thesacSgene encoding a positive regulator of the sucrose regulon inBacillus subtilis

The sacS gene controls the expression of 2 saccharolytic enzymes in Bacillus subtilis (sucrase and levansucrase). This paper describes a recombinant plasmid containing a mutant allele, sacSc. The plasmid was isolated from a B. subtilis DNA bank established in Escherichia coli. Moreover, it was shown that the sacSc allele, placed on a high-copy plasmid, is dominant over the wild-type chromosomal sacS+ allele. This result strongly suggests that the sacS gene encodes a positive regulatory protein.