Effect of netropsin on the derepression of enzymes during growth and sporulation of Bacillus subtilis

Netropsin, a polypeptide antibiotic which binds specifically to adenylate thymidylate rich regions of deoxyribonucleic acid, inhibits sporulation at about stage II, but does not inhibit growth of B. subtilis. An analysis of the sporulation associated enzymes aconitase, alkaline phosphatase, and glucose dehydrogenase revealed that their rates of expression were not affected by the presence of the antibiotic. The derepression of histidase, a vegetatively induced enzyme, was stimulated by netropsin. Oxygen utilization by the cells during sporulation was not effected nor was spore germination prevented by the drug. Netropsin, however, did prevent the formation of dipicolinic acid. These and earlier results suggest that netropsin may be affecting the transcription of only select sporulation genes that are particularly rich in adenylate thymidylate base pairs.