Tirandamycin, an Inhibitor of Bacterial Ribonucleic Acid Polymerase
AUTOR(ES)
Reusser, Fritz
RESUMO
The antibiotic tirandamycin (a 3-acyltetramic acid structurally related to streptolydigin) specifically inhibits transcription by interfering with the function of bacterial ribonucleic acid polymerase. Ribonucleic acid polymerases from rat liver nuclei are not subject to tirandamycin inhibition. Qualitatively, the mode of action of the antibiotic is identical to that of streptolydigin in inhibiting chain initiation as well as chain elongation during the transcriptional process. However, tirandamycin is approximately 40 times less potent than streptolydigin. The structures of the 3-acyl groups of the two acyltetramic acid antibiotics tirandamycin and streptolydigin differ only slightly in the degree of oxidation of the terminal dioxabicyclo (3.1)nonane system and possess the same stereochemistry (D. J. Duchamp, A. R. Branfman, A. C. Button, and K. L. Rinehart, 1973). More significantly, major differences occur at the 1 and 5 positions of the tetramic acids. Tirandamycin contains no substituents; streptolydigin contains a substituted acetamide function at position 5 and a sugar moiety at position 1. The lack of substituents at the 1 and 5 positions of the tetramic acid portion in tirandamycin is probably responsible for the reduced biopotency of tirandamycin as compared with streptolydigin.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=429803Documentos Relacionados
- Tirandamycin: Inhibition of Ribonucleic Acid Polymerase
- Characterization of an inhibitor of ribonucleic acid polymerase from the mycelial phase of Histoplasma capsulatum.
- Lomofungin, an Inhibitor of Deoxyribonucleic Acid-Dependent Ribonucleic Acid Polymerases
- Bacterial lipopolysaccharide induction of a mouse spleen factor stimulating ribonucleic acid polymerase II.
- Rapid micromethod for the purification of Escherichia coli ribonucleic acid polymerase and the preparation of bacterial extracts active in ribonucleic acid synthesis.