The mechanism of action of myxovalargin A, a peptide antibiotic from Myxococcus fulvus.
Myxovalargin A has two modes of action. At low concentrations (below 1 microgram/ml) it inhibits bacterial protein synthesis specifically and instantaneously. In vitro experiments suggest that it interferes with the binding of aminoacyl tRNA to the A site of the ribosome. At higher concentrations (above 5 micrograms/ml), or upon prolonged incubation, the antibiotic damages cell membranes. This leads to secondary effects, like decreased O2 consumption or instant break down of RNA synthesis, and may be the reason for the irreversibility of the antibiotic action. The membrane effect is not restricted to prokaryotes and may explain the high toxicity of the compound for higher organisms.
Irschik
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H
Reichenbach
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D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D009231:Myxococcales / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010452:Peptide Biosynthesis; D010455:Peptides / Q000494:pharmacology; D012329:RNA, Bacterial / Q000096:biosynthesis; D011817:Rabbits
D000900:Anti-Bacterial Agents; D010455:Peptides; D012329:RNA, Bacterial; C042512:myxovalargins