Effect of Gramicidin S on the Transcription System of the Producer Bacillus brevis Nagano

Abstract

The effect of the peptide antibiotic gramicidin S, produced by Bacillus brevis Nagano, was tested on the transcription system of the producer by using in vivo, semi in vitro and in vitro systems for studies of RNA synthesis. The effects of other peptide antibiotics (linear gramicidin, tyrocidine and tyrothricin) were also tested for comparison. It was found that (a) RNA polymerase isolated from either gramicidin S-producing or non-producing strains had a similar structure and requirements and that (b) the presence of gramicidin S caused a very strong inhibition of the in vitro transcription system. We present evidence that this inhibition is most probably through formation of a complex between the antibiotic and the DNA. In vivo studies indicate that transcription during growth and sporulation is not affected by gramicidin S and the implication is made that gramicidin S inhibits transcription during germination and outgrowth.

Biosynthesis, Molecular Regulation, and Application of Bacilysin Produced by Bacillus Species

“…Thus, this peptide may be involved in gene regulation during sporulation [ 9 ]. A slightly different result was reported in the case of the peptide antibiotic gramicidin S, as it was observed that gramicidin S did not inhibit transcription during growth and sporulation, but it inhibited transcription during germination and outgrowth [ 10 ]. Sporulation was induced by supplementary peptide antibiotics in B. brevis when the cells were grown under low-nitrogen concentration in the culture medium [ 11 ].…”

Antimicrobial Bacillus: Metabolites and Their Mode of Action

“…Gramicidin S interacts with the plasma membrane by forming oligomeric β-barrel pores, which destroys the barrier properties of the membrane [ 56 , 57 ]. Further in vivo studies have shown that gramicidin S binds to the DNA and inhibits transcription and cell growth [ 58 ].…”

Biochemistry, genetics and regulation of bacilysin biosynthesis and its significance more than an antibiotic

“…Beyond their antimicrobial activities, the functions of peptide antibiotics in their producers have been the subject of speculation and discussions long before the common master players of these processes became identified [1,2,76,[91][92][93][94]. Function in sporulation, germination and outgrowth have been suggested.…”