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Journal of Bacteriology Oct 1987A 6.8-kilobase-pair (kbp) transposable element (Tn4556) was found in a neomycin-producing strain of Streptomyces fradiae. This element was first observed in two 30.3-kbp...
A 6.8-kilobase-pair (kbp) transposable element (Tn4556) was found in a neomycin-producing strain of Streptomyces fradiae. This element was first observed in two 30.3-kbp plasmids (pUC1123 and pUC1124) which arose when a thiostrepton resistance gene (1 kbp) was ligated with the BclI-2 fragment (22.5 kbp) that contains the origin of replication of phage SF1. The Tn4556 segment was deleted when these plasmids were transduced into another S. fradiae host with phage SF1. These deletion plasmids (pUC1210 and pUC1211) had copy numbers of less than 1 per chromosome and were unstable. In contrast, pUC1123 and pUC1124, with copy numbers of 12 to 15 per chromosome, respectively, were relatively stable. When pUC1210 and pUC1211 were reintroduced into S. fradiae by protoplast transformation, the Tn4556 element transposed again to the plasmids at numerous new locations in either of two orientations. A copy of Tn4556 was found in the S. fradiae chromosome by hybridization studies. It appears that Tn4556 originated from the chromosome, transposed into unstable pUC1210 and pUC1211, and made stable plasmids. A temperature-sensitive hybrid plasmid carrying a viomycin resistance derivative of Tn4556 (pMT660::Tn4556::vph) was constructed. When Streptomyces lividans UC8390 containing the hybrid plasmid was grown at 39 degrees C, Tn4556::vph (Tn4560) transposed to random positions in the host chromosome.
Topics: Cloning, Molecular; DNA Restriction Enzymes; DNA Transposable Elements; DNA, Bacterial; Drug Resistance, Microbial; Genes, Bacterial; Genetic Vectors; Nucleic Acid Hybridization; Plasmids; Streptomyces; Thiostrepton; Transduction, Genetic; Transformation, Bacterial
PubMed: 2820925
DOI: 10.1128/jb.169.10.4436-4441.1987 -
Nucleic Acids Research Dec 1980Binding studies were performed with a [14C]-labelled derivative of viomycin, tuberactinomycin 0 (TUM O). TUM O bound to 30S and 50S subunits. The binding component was...
Binding studies were performed with a [14C]-labelled derivative of viomycin, tuberactinomycin 0 (TUM O). TUM O bound to 30S and 50S subunits. The binding component was the RNA, since ribosomal proteins did not bind the drug. Other RNAs such as tRNA, phage RNA (MS2), and homopolynucleotides also bound the drug. Striking differences in the binding capacity of the various homopolynucleotides were found. Poly(U) bound strongly, poly(G) and poly(C) bound intermediately, whereas poly(A) showed a very low binding. DNA also bound TUM O, although with native DNA the binding was only weak. Finally the effects of viomycin on the assembly in vitro of the 50S subunit from E. coli were tested. A very strong inhibition was found: when the reconstitution was performed at 0.5 x 10(-6) M viomycin the particles formed sedimented at about 50S, but showed a residual activity of less than 10%. The inhibitory power of viomycin with respect to the in vitro assembly is more pronounced than that found in in vitro systems for protein synthesis.
Topics: Binding Sites; Enviomycin; Escherichia coli; Mycobacterium; Nucleic Acid Conformation; Polyribonucleotides; RNA, Ribosomal; Ribosomes; Viomycin
PubMed: 6258151
DOI: 10.1093/nar/8.23.5767 -
The Journal of Antibiotics Mar 1989The appropriate location and orientation of the kanamycin resistance gene (kmr) cloned on multicopy plasmids were determined by subcloning experiments. The transcription...
The appropriate location and orientation of the kanamycin resistance gene (kmr) cloned on multicopy plasmids were determined by subcloning experiments. The transcription start site was identified by high-resolution S1 mapping and the kmr mRNA was shown to have a long leader of about 400 bp. An additional transcript upstream of the kmr gene was also detected, which ran in the opposite direction and overlapped 2 to 3 nucleotides with the kmr transcript. The presumptive promoter region of this physiologically unidentified RNA was similar to the Escherichia coli promoter consensus sequence both in the -10 and -35 regions, whereas the putative promoter region of the kmr gene exhibited sequence similarities in the -10 region to the promoters of the endoglycosidase H (endoH) and the viomycin phosphotransferase (vph) genes from Streptomyces.
Topics: Base Sequence; Chromosome Mapping; Drug Resistance, Microbial; Kanamycin; Molecular Sequence Data; Promoter Regions, Genetic; Streptomyces; Transcription, Genetic
PubMed: 2708135
DOI: 10.7164/antibiotics.42.413 -
The FEBS Journal Feb 2005Stringent factor is a ribosome-dependent ATP:GTP pyrophosphoryl transferase that synthesizes (p)ppGpp upon nutrient deprivation. It is activated by unacylated tRNA in...
Stringent factor is a ribosome-dependent ATP:GTP pyrophosphoryl transferase that synthesizes (p)ppGpp upon nutrient deprivation. It is activated by unacylated tRNA in the ribosomal amino-acyl site (A-site) but it is unclear how activation occurs. A His-tagged stringent factor was isolated by affinity-chromatography and precipitation. This procedure yielded a protein of high purity that displayed (a) a low endogenous pyrophosphoryl transferase activity that was inhibited by the antibiotic tetracycline; (b) a low ribosome-dependent activity that was inhibited by the A-site specific antibiotics thiostrepton, micrococcin, tetracycline and viomycin; (c) a tRNA- and ribosome-dependent activity amounting to 4500 pmol pppGpp per pmol stringent factor per minute. Footprinting analysis showed that stringent factor interacted with ribosomes that contained tRNAs bound in classical states. Maximal activity was seen when the ribosomal A-site was presaturated with unacylated tRNA. Less tRNA was required to reach maximal activity when stringent factor and unacylated tRNA were added simultaneously to ribosomes, suggesting that stringent factor formed a complex with tRNA in solution that had higher affinity for the ribosomal A-site. However, tRNA-saturation curves, performed at two different ribosome/stringent factor ratios and filter-binding assays, did not support this hypothesis.
Topics: Base Sequence; DNA Primers; Electrophoresis, Polyacrylamide Gel; Escherichia coli; GTP Pyrophosphokinase; Guanosine Pentaphosphate; RNA, Transfer, Met; Recombinant Proteins; Ribosomes
PubMed: 15670150
DOI: 10.1111/j.1742-4658.2004.04502.x -
Nature Communications Sep 2014The antibiotic streptomycin is widely used in the treatment of microbial infections. The primary mechanism of action is inhibition of translation by binding to the...
The antibiotic streptomycin is widely used in the treatment of microbial infections. The primary mechanism of action is inhibition of translation by binding to the ribosome, but how it enters the bacterial cell is unclear. Early in the study of this antibiotic, a mysterious streptomycin-induced potassium efflux preceding any decrease in viability was observed; it was speculated that this changed the electrochemical gradient such that streptomycin better accessed the cytoplasm. Here we use a high-throughput screen to search for compounds targeting the mechanosensitive channel of large conductance (MscL) and find dihydrostreptomycin among the 'hits'. Furthermore, we find that MscL is not only necessary for the previously described streptomycin-induced potassium efflux, but also directly increases MscL activity in electrophysiological studies. The data suggest that gating MscL is a novel mode of action of dihydrostreptomycin, and that MscL's large pore may provide a mechanism for cell entry.
Topics: Anti-Bacterial Agents; Dihydrostreptomycin Sulfate; Escherichia coli; Escherichia coli Proteins; High-Throughput Screening Assays; Ion Channels; Patch-Clamp Techniques; Potassium; Spectinomycin; Streptomycin; Viomycin
PubMed: 25205267
DOI: 10.1038/ncomms5891 -
Bulletin of the World Health... 1973The first International Reference Preparation of Viomycin was replaced by the second international reference preparation, consisting of material from the batch that...
The first International Reference Preparation of Viomycin was replaced by the second international reference preparation, consisting of material from the batch that provided the second Working Standard of the US Food and Drug Administration. The International Unit of viomycin was redefined as the activity contained in 0.0012285 mg of the second international reference preparation. Examination of batches of viomycin sulfate from the various sources of production showed that the second international reference preparation was suitable for their assay, whereas a sample previously proposed as the international standard of viomycin was unsatisfactory.
Topics: International Cooperation; Viomycin; World Health Organization
PubMed: 4352612
DOI: No ID Found -
FEBS Letters Jan 1985The binding of 14C-labelled tuberactinomycin O was analysed in equilibrium dialysis cells. The ionic conditions and the concentration of the labelled drug used in the...
The binding of 14C-labelled tuberactinomycin O was analysed in equilibrium dialysis cells. The ionic conditions and the concentration of the labelled drug used in the binding assays allowed the binding of just one drug molecule per non-programmed ribosome. Under these conditions, the occupation of the ribosomal P-site by deacylated tRNAPhe in the presence of poly(U) increased the amount of [14C]tuberactinomycin O bound by a factor of two. Kanamycin, gentamicin and neomycin reduced the binding of tuberactinomycin O, whereas chloramphenicol, tetracycline, streptomycin and puromycin had no effect. A stimulation of the binding of tuberactinomycin O was found upon addition of erythromycin.
Topics: Anti-Bacterial Agents; Carbon Radioisotopes; Enviomycin; Escherichia coli; RNA, Transfer; Ribosomes; Urea; Viomycin
PubMed: 2981179
DOI: 10.1016/0014-5793(85)80186-1 -
Journal of Bacteriology Aug 1982Determinants of antibiotic resistance have been cloned from four antibiotic-producing streptomycetes into Streptomyces lividans. Biochemical analyses of resistant clones...
Determinants of antibiotic resistance have been cloned from four antibiotic-producing streptomycetes into Streptomyces lividans. Biochemical analyses of resistant clones revealed the presence of enzymes that had previously been characterized as likely resistance determinants in the producing organisms. These included: 23S rRNA methylases from S. azureus and S. erythreus, which confer resistance to thiostrepton and erythromycin, respectively; viomycin phosphotransferase from S. vinaceus; and aminoglycoside phosphotransferase and acetyltransferase from the neomycin producer S. fradiae. In general, the levels of antibiotic resistance of the clones were similar to those of the producing organisms. Although the two aminoglycoside-modifying enzymes from S. fradiae could independently confer only low-level resistance to neomycin, the presence of both enzymes in the same strain resulted in a level of resistance comparable with that of the producing organism.
Topics: Acetyltransferases; Anti-Bacterial Agents; Cloning, Molecular; Erythromycin; Kanamycin Kinase; Methyltransferases; Phosphotransferases; R Factors; Streptomyces; Thiostrepton
PubMed: 6284707
DOI: 10.1128/jb.151.2.678-685.1982 -
Journal of Bacteriology Mar 1987The viomycin phosphotransferase gene (vph) is expressed and confers resistance to viomycin in both Streptomyces spp. and members of the family Enterobacteriaceae. We...
The viomycin phosphotransferase gene (vph) is expressed and confers resistance to viomycin in both Streptomyces spp. and members of the family Enterobacteriaceae. We report the isolation of UGA (opal) and UAG (amber) mutations in the vph gene of shuttle plasmid pVE138. We found that the five UGA mutations in vph resulted in a temperature-sensitive phenotype in Salmonella typhimurium. Su- strains are Vior at 28 degrees C and Vios at 37 degrees C, whereas Su+UGA strains are Vior at both 28 and 37 degrees C. The single amber mutation isolated was not temperature sensitive and resulted in the expected Vios phenotype in Su- strains and Vior in Su+UAG strains.
Topics: DNA Restriction Enzymes; Escherichia coli; Genes; Genes, Bacterial; Kanamycin Kinase; Mutation; Phosphotransferases; Salmonella typhimurium; Streptomyces; Suppression, Genetic
PubMed: 3029035
DOI: 10.1128/jb.169.3.1325-1327.1987 -
Postgraduate Medical Journal Sep 1964
Topics: Adolescent; Aminosalicylic Acid; Aminosalicylic Acids; Child; Drug Therapy; Ethionamide; Humans; Isoniazid; Knee Joint; Pyrazinamide; Radiography; Streptomycin; Surgical Procedures, Operative; Toxicology; Tuberculosis; Tuberculosis, Osteoarticular; Viomycin
PubMed: 14186293
DOI: 10.1136/pgmj.40.467.549