Recovery of metabolic activity in Escherichia coli following limited exposure to myxin

Abstract

Exposure of Escherichia coli to myxin results in the inhibition of DNA synthesis and the cells are killed rapidly. The results presented here indicate that after a short exposure, the removal of myxin allows DNA synthesis to be renewed at the normal rate for a significant period of time before DNA synthesis is again inhibited. This metabolic recovery of DNA synthesis has been shown to be dependent on protein synthesis occurring both during and after exposure to this antibiotic. The protein involved may be one of the DNA-repair enzymes known to be present in these cells. The lethal effect of myxin, therefore, is not due to inhibition of DNA synthesis directly but is probably the result of irreparable damage to the DNA template. This interpretation is supported by the results of similar experiments showing the metabolic recovery of RNA synthesis, which follows a pattern almost identical with that seen with DNA.