Lomofungin, an inhibitor of deoxyribonucleic acid-dependent ribonucleic acid polymerases
Antimicrobial Agents and Chemotherapy
|June 1, 1973
Abstract:
Lomofungin, an antibiotic active against fungi, yeasts, and bacteria, was found to be a potent inhibitor of purified Escherichia coli deoxyribonucleic acid (DNA)-dependent ribonucleic acid (RNA) polymerase. It prevents RNA synthesis by a direct interaction with the polymerase and not with the template or substrate; chain elongation is halted promptly. Three DNA-dependent RNA polymerases isolated from Saccharomyces strain 1016 were also sensitive to the antibiotic. Lomofungin does not appear to react generally with proteins, as bovine serum albumin did not prevent the inhibitory effect and numerous other enzymes were not affected by lomofungin.
Insights
Lomofungin, an antibiotic, potently inhibits bacterial and yeast RNA polymerase, halting RNA synthesis by directly binding to the enzyme. This antibiotic shows specific action against RNA polymerase, not broadly affecting proteins.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Lomofungin is an antibiotic with known activity against fungi, yeasts, and bacteria.
- Deoxyribonucleic acid (DNA)-dependent ribonucleic acid (RNA) polymerase is a crucial enzyme for transcription in all living organisms.
- Understanding the mechanisms of action for novel antibiotics is vital for combating microbial resistance.
Purpose of the Study:
- To investigate the molecular mechanism by which lomofungin inhibits microbial growth.
- To determine if lomofungin targets bacterial and/or eukaryotic RNA polymerase.
- To assess the specificity of lomofungin's interaction with enzymes.
Main Methods:
- Purification of Escherichia coli DNA-dependent RNA polymerase.
- Testing the inhibitory effect of lomofungin on purified RNA polymerase activity.
- Isolation and testing of RNA polymerases from Saccharomyces strain 1016.
- Assessing lomofungin's effect on non-target proteins like bovine serum albumin and other enzymes.
Main Results:
- Lomofungin was identified as a potent inhibitor of purified Escherichia coli DNA-dependent RNA polymerase.
- The antibiotic directly interacts with the RNA polymerase enzyme, halting RNA synthesis and chain elongation.
- RNA polymerases isolated from Saccharomyces strain 1016 were also sensitive to lomofungin.
- Lomofungin did not show general reactivity with proteins; bovine serum albumin did not counteract its inhibitory effect, and other enzymes were unaffected.
Conclusions:
- Lomofungin specifically inhibits DNA-dependent RNA polymerase in both bacteria and yeast.
- The mechanism of action involves direct binding to the polymerase, disrupting RNA synthesis.
- Lomofungin represents a potential therapeutic agent targeting essential transcriptional machinery in microbes.
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