Trans-acting regulation of antibiotic TA genes in Myxococcus xanthus

Two regulatory mutations of Myxococcus xanthus, which cause an increase in the transcription of genes required for antibiotic TA synthesis, were mapped by transduction and their effect on transcription of four TA genes examined. The two regulatory mutations were closely linked and located within the 40-kb TA gene cluster on the M. xanthus chromosome. Recombinants were constructed which contained one of the regulatory mutations and promoter probes in the four different TA genes. Both regulatory mutations enhanced transcription of three of the four TA genes. However, construction of a strain containing the over-expression regulatory mutation in a wild-type background produced less antibiotic than the parental strain.