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The Journal of Antibiotics Feb 1979Skeletal muscle actin was found by centrifugation, turbidity, and viscosity measurements to form polymers upon addition of aminoglycosides, viomycin, polymyxin B, and...
Skeletal muscle actin was found by centrifugation, turbidity, and viscosity measurements to form polymers upon addition of aminoglycosides, viomycin, polymyxin B, and tetracycline. A linear relationship was observed between the amount of actin polymerization and the number of primary amino groups on the aminoglycoside antibiotics except kanamycin. Of the antibiotics studied, neomycin was most efficient in actin polymerization. Polymerization of actin was not significantly induced by kasugamycin, chloramphenicol, erythromycin, benzylpenicillin, angustmycin A, formycin, actinomycin D, and mitomycin C. Aminoglycosides and viomycin were demonstrated to inhibit the acto-HMM Mg(2+)-ATPase reaction but did not significantly affect HMM Mg(2+)-ATPase activity. It was found by equilibrium dialysis that [(3)H]dihydrostreptomycin bound to actin.
Topics: Actins; Adenosine Triphosphatases; Aminoglycosides; Animals; Anti-Bacterial Agents; Chemical Phenomena; Chemistry; Dialysis; In Vitro Techniques; Nephelometry and Turbidimetry; Polymers; Protein Binding; Rabbits; Viscosity
PubMed: 155669
DOI: 10.7164/antibiotics.32.156 -
The EMBO Journal May 2002Ribosome recycling factor (RRF) together with elongation factor G (EF-G) disassembles the post- termination ribosomal complex. Inhibitors of translocation, thiostrepton,...
Ribosome recycling factor (RRF) together with elongation factor G (EF-G) disassembles the post- termination ribosomal complex. Inhibitors of translocation, thiostrepton, viomycin and aminoglycosides, inhibited the release of tRNA and mRNA from the post-termination complex. In contrast, fusidic acid and a GTP analog that fix EF-G to the ribosome, allowing one round of tRNA translocation, inhibited mRNA but not tRNA release from the complex. The release of tRNA is a prerequisite for mRNA release but partially takes place with EF-G alone. The data are consistent with the notion that RRF binds to the A-site and is translocated to the P-site, releasing deacylated tRNA from the P- and E-sites. The final step, the release of mRNA, is accompanied by the release of RRF and EF-G from the ribosome. With the model post-termination complex, 70S ribosomes were released from the post-termination complex by the RRF reaction and were then dissociated into subunits by IF3.
Topics: Escherichia coli; Macromolecular Substances; Peptide Chain Termination, Translational; Peptide Elongation Factor G; Protein Synthesis Inhibitors; Proteins; RNA, Messenger; RNA, Transfer; Ribosomal Proteins; Ribosomes
PubMed: 11980724
DOI: 10.1093/emboj/21.9.2272 -
Journal of Natural Products Apr 2007The nonproteinogenic amino acid capreomycidine is the signature residue found in the tuberactinomycin family of antitubercular peptide antibiotics and an important...
The nonproteinogenic amino acid capreomycidine is the signature residue found in the tuberactinomycin family of antitubercular peptide antibiotics and an important element of the pharmacophore. Recombinant VioG, a single-module peptide synthetase from the viomycin gene cluster cloned from Streptomyces vinaceus (ATCC11861), specifically activates capreomycidine for incorporation into viomycin (tuberactinomycin B). Insertional disruption of the putative hydroxylase gene vioQ resulted in a mutant that accumulated tuberactinomycin O, suggesting that hydroxylation at C-5 of the capreomycidine residue is a post-assembly event. The inactivated chromosomal copy of vioQ could be complemented with a wild-type copy of the gene to restore viomycin production.
Topics: Anti-Bacterial Agents; Base Sequence; Escherichia coli; Genes, Bacterial; Molecular Structure; Peptide Synthases; Streptomyces; Viomycin
PubMed: 17302456
DOI: 10.1021/np060605u -
The Journal of Biological Chemistry Nov 2003Elongation factor G (EF-G) and ribosome recycling factor (RRF) disassemble post-termination complexes of ribosome, mRNA, and tRNA. RRF forms stable complexes with 70 S...
Elongation factor G (EF-G) and ribosome recycling factor (RRF) disassemble post-termination complexes of ribosome, mRNA, and tRNA. RRF forms stable complexes with 70 S ribosomes and 50 S ribosomal subunits. Here, we show that EF-G releases RRF from 70 S ribosomal and model post-termination complexes but not from 50 S ribosomal subunit complexes. The release of bound RRF by EF-G is stimulated by GTP analogues. The EF-G-dependent release occurs in the presence of fusidic acid and viomycin. However, thiostrepton inhibits the release. RRF was shown to bind to EF-G-ribosome complexes in the presence of GTP with much weaker affinity, suggesting that EF-G may move RRF to this position during the release of RRF. On the other hand, RRF did not bind to EF-G-ribosome complexes with fusidic acid, suggesting that EF-G stabilized by fusidic acid does not represent the natural post-termination complex. In contrast, the complexes of ribosome, EF-G and thiostrepton could bind RRF, although with lower affinity. These results suggest that thiostrepton traps an intermediate complex having RRF on a position that clashes with the P/E site bound tRNA. Mutants of EF-G that are impaired for translocation fail to disassemble post-termination complexes and exhibit lower activity in releasing RRF. We propose that the release of ribosome-bound RRF by EF-G is required for post-termination complex disassembly. Before release from the ribosome, the position of RRF on the ribosome will change from the original A/P site to a new location that clashes with tRNA on the P/E site.
Topics: Dose-Response Relationship, Drug; Escherichia coli; Fusidic Acid; Guanosine Triphosphate; Hydrolysis; Kinetics; Models, Biological; Mutation; Peptide Elongation Factor G; Protein Binding; Protein Transport; RNA, Messenger; RNA, Transfer; Ribosomes; Thiostrepton; Time Factors; Viomycin
PubMed: 12960150
DOI: 10.1074/jbc.M304834200 -
Antimicrobial Agents and Chemotherapy Mar 1979The in vitro activities of 39 antimicrobial agents against 23 isolates of Treponema hyodysenteriae, the majority of which were field isolates, were determined by the...
The in vitro activities of 39 antimicrobial agents against 23 isolates of Treponema hyodysenteriae, the majority of which were field isolates, were determined by the agar dilution technique. Quinoxalines, pleuromutilin, nitroimidazoles, and nitrofuran were the most active. Their activities ranged from =0.10 to 1.56 mug/ml. Lincomycin, penicillins, chloramphenicol, tetracyclines, cephalosporins, three peptides (virginiamycin, thiopeptin, and bacitracin), and one aminoglycoside (gentamicin) exhibited intermediate levels of activity ranging from 0.39 to 50 mug/ml. Four peptides (enduracidin, viomycin, bicyclomycin, and colistin), three aminoglycosides (kanamycin, streptomycin, and neomycin), polyene, and other agents, including novobiocin, vancomycin, rifampin, nalidixic acid, and p-arsanilic acid, displayed limited activities ranging from 12.5 to >/=100 mug/ml. Macrolides showed varying degrees of activity depending upon isolates.
Topics: Anaerobiosis; Anti-Bacterial Agents; Culture Media; Feces; Microbial Sensitivity Tests; Treponema
PubMed: 464566
DOI: 10.1128/AAC.15.3.392 -
Chembiochem : a European Journal of... Aug 2011
Topics: Antitubercular Agents; Bacterial Proteins; Capreomycin; Chromatography, High Pressure Liquid; DNA Primers; Escherichia coli; Extensively Drug-Resistant Tuberculosis; Metabolic Engineering; Mycobacterium tuberculosis; Peptide Biosynthesis, Nucleic Acid-Independent; Peptide Synthases; Plasmids; Recombinant Proteins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptomyces lividans; Structural Homology, Protein; Transformation, Genetic; Viomycin
PubMed: 21739558
DOI: 10.1002/cbic.201100193 -
Molecular Cell Jul 2006The cyclic peptide antibiotics capreomycin and viomycin are generally effective against the bacterial pathogen Mycobacterium tuberculosis. However, recent virulent...
The cyclic peptide antibiotics capreomycin and viomycin are generally effective against the bacterial pathogen Mycobacterium tuberculosis. However, recent virulent isolates have become resistant by inactivation of their tlyA gene. We show here that tlyA encodes a 2'-O-methyltransferase that modifies nucleotide C1409 in helix 44 of 16S rRNA and nucleotide C1920 in helix 69 of 23S rRNA. Loss of these previously unidentified rRNA methylations confers resistance to capreomycin and viomycin. Many bacterial genera including enterobacteria lack a tlyA gene and the ensuing methylations and are less susceptible than mycobacteria to capreomycin and viomycin. We show that expression of recombinant tlyA in Escherichia coli markedly increases susceptibility to these drugs. When the ribosomal subunits associate during translation, the two tlyA-encoded methylations are brought into close proximity at interbridge B2a. The location of these methylations indicates the binding site and inhibitory mechanism of capreomycin and viomycin at the ribosome subunit interface.
Topics: Antibiotics, Antitubercular; Bacterial Proteins; Base Sequence; Capreomycin; Cloning, Molecular; Drug Resistance, Bacterial; Escherichia coli; Mass Spectrometry; Methylation; Molecular Sequence Data; Mutation; Mycobacteriaceae; Nucleic Acid Conformation; RNA, Bacterial; RNA, Ribosomal, 16S; RNA, Ribosomal, 28S; Recombinant Proteins; Ribosomes
PubMed: 16857584
DOI: 10.1016/j.molcel.2006.05.044 -
Molecular Cell Feb 2007Translocation requires large-scale movements of ribosome-bound tRNAs. Using tRNAs that are proflavin labeled and single-turnover rapid kinetics assays, we identify one...
Translocation requires large-scale movements of ribosome-bound tRNAs. Using tRNAs that are proflavin labeled and single-turnover rapid kinetics assays, we identify one or possibly two kinetically competent intermediates in translocation. EF-G.GTP binding to the pretranslocation (PRE) complex and GTP hydrolysis are rapidly followed by formation of the securely identified intermediate complex (INT), which is more slowly converted to the posttranslocation (POST) complex. Peptidyl tRNA within the INT complex occupies a hybrid site, which has a puromycin reactivity intermediate between those of the PRE and POST complexes. Thiostrepton and viomycin inhibit INT formation, whereas spectinomycin selectively inhibits INT disappearance. The effects of other translocation modulators suggest that EF-G-dependent GTP hydrolysis is more important for INT complex formation than for INT complex conversion to POST complex and that subtle changes in tRNA structure influence coupling of tRNA movement to EF-G.GTP-induced conformational changes.
Topics: Anti-Bacterial Agents; Escherichia coli; Fluorescence; Guanosine Triphosphate; Hydrolysis; Kinetics; Models, Genetic; Mutation; N-Formylmethionine; Nucleic Acid Conformation; Peptide Elongation Factor G; Protein Biosynthesis; Puromycin; RNA Transport; RNA, Transfer
PubMed: 17317625
DOI: 10.1016/j.molcel.2007.01.014 -
Antimicrobial Agents and Chemotherapy Jul 1974Viomycin-resistant strains isolated from Mycobacterium smegmatis demonstrated pleiotropic resistance to tuberactinomycin-N, capreomycin, streptomycin, and kanamycin as a...
Viomycin-resistant strains isolated from Mycobacterium smegmatis demonstrated pleiotropic resistance to tuberactinomycin-N, capreomycin, streptomycin, and kanamycin as a result of mutational alteration of ribosomes, even though they were selected for resistance to a single antibiotic. The pleiotropic drug resistance of three mutants isolated by stepwise selection for resistance to viomycin was due to alteration of the 30S ribosomal subunit. One mutant, strain A, isolated independently by multiple-step selection to viomycin resistance, was resistant to viomycin, tuberactinomycin-N, and capreomycin through an alteration of the 50S ribosomal subunit, whereas it was sensitive to kanamycin but resistant to streptomycin through an alteration of the 30S ribosomal subunit. Three streptomycin-resistant strains, which were isolated by one-step selection at a high concentration of streptomycin, did not show significant co-resistance to any other antibiotics tested in culture and cell-free systems; streptomycin resistance in these mutants was localized on the 30S ribosomal subunit.
Topics: Drug Resistance, Bacterial; Mutation; Mycobacterium smegmatis; Ribosomes; Streptomycin; Viomycin
PubMed: 15828170
DOI: 10.1128/AAC.6.1.46 -
Proceedings of the National Academy of... Sep 1981The binding of N-acetyl-Phe-tRNAPhe (an analogue of peptidyl-tRNA), Phe-tRNAPhe, and deacylated tRNAPhe to poly(U)-programmed tightly coupled 70S ribosomes was studied....
The binding of N-acetyl-Phe-tRNAPhe (an analogue of peptidyl-tRNA), Phe-tRNAPhe, and deacylated tRNAPhe to poly(U)-programmed tightly coupled 70S ribosomes was studied. The N-acetyl-Phe-tRNAPhe binding is governed by an exclusion principle: not more than one N-acetyl-Phe-tRNAPhe can be bound per ribosome, although this peptidyl-tRNA analogue can be present either at the aminoacyl-tRNA (A) site or the peptidyl-tRNA (P) site. Two Phe-tRNAPhe molecules are accepted by one ribosome in the presence of poly(U). This aminoacyl-tRNA binds enzymatically (in the presence of elongation factor Tu and GTP) and nonenzymatically to the A site and is then transferred to the P site, if that site is free. If this elongation factor G-independent movement is hampered, either by using an incubation temperature of 0 degrees C or by the addition of the translocation inhibitor viomycin, only one Phe-tRNAPhe per ribosome can be bound. The effect of the peptidyltransferase inhibitor chloramphenicol on the binding is similar to that of viomycin. In the absence of poly(U), Phe-tRNAPhe cannot bind to the ribosome. Deacylated [14C]tRNAPhe can bind in three copies to one ribosome. The new third tRNA binding site is called the "E" site. The sequence of filling the sites is P, E, and A. The apparent binding constants for the P and the E sites are both approximately 9 X 10(6) M-1 and that for the A site is 1.3 X 10(6) M-1. In the absence of poly(U), only one deacylated tRNAPhe can be bound per ribosome. This tRNAPhe most likely occupies the P site.
Topics: Binding Sites; Escherichia coli; Peptide Elongation Factors; RNA, Messenger; RNA, Transfer; RNA, Transfer, Amino Acyl; Ribosomes
PubMed: 7029532
DOI: 10.1073/pnas.78.9.5310