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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 -
Microbiology and Immunology 1987
Comparative Study
Topics: Enviomycin; Escherichia coli; Mycobacterium; Mycobacterium bovis; Ribosomes; Viomycin
PubMed: 3037284
DOI: 10.1111/j.1348-0421.1987.tb03081.x -
European Journal of Biochemistry Dec 1986The standard technique for determination of the ribosomal site location of bound tRNA, viz. the puromycin reaction, has been analyzed with regard to its applicability...
The standard technique for determination of the ribosomal site location of bound tRNA, viz. the puromycin reaction, has been analyzed with regard to its applicability under tRNA saturation conditions. The criteria derived have been used to re-examine the exclusion principle for peptidyl-tRNA binding, which states that only one peptidyl-tRNA (AcPhe-tRNA) can be bound per ribosome although in principle two sites (A and P site) are available. The following results were obtained. The puromycin reaction is only appropriate for a site determination if the reaction conditions prevent one ribosome from performing more than one puromycin reaction. With an excess of AcPhe-tRNA over ribosomes, and in the absence of EF-G, this criterion is fulfilled at 0 degree C, where the P-site-bound material reacts with puromycin (quantitative reaction after 50 h), while the A-site-bound material does not. In contrast, at 37 degrees C the extent of the puromycin reaction can exceed the binding values by 2-4-fold ('repetitive reaction'). In the presence of EF-G a repetitive puromycin reaction is seen even at 0 degree C, i.e. EF-G can already promote a translocation reaction at 0 degree C. However, the extent of translocation becomes negligibly low for short incubation times (up to 60 min) at 0 degree C, if only catalytic amounts of EF-G are used. Using the criteria outlined above, the validity of the exclusion principle for Escherichia coli ribosomes was confirmed pursuing two different experimental strategies. Ribosomes were saturated with AcPhe-tRNA at one molecule per 70S ribosome, and a quantitative puromycin reaction demonstrated the exclusive P-site location of the AcPhe-tRNA. The same result was also found in the presence of viomycin, which blocks the translocation reaction. These findings also indicate that here nearly 100% of the ribosomes participate in AcPhe-tRNA binding to the P site. Precharging the P sites of 70S ribosomes with one Ac[14C]Phe-tRNA molecule per ribosome prevented additional Ac[3H]Phe-tRNA binding. In contrast, 70S particles carrying one molecule of [14C]tRNAPhe per ribosome were able to bind up to a further 0.64 molecule Ac[3H]Phe-tRNA per ribosome.
Topics: Binding Sites; Binding, Competitive; Kinetics; Peptide Elongation Factor G; Peptide Elongation Factors; Puromycin; RNA, Transfer, Amino Acyl; Ribosomes; Temperature; Viomycin
PubMed: 3024981
DOI: 10.1111/j.1432-1033.1986.tb10498.x -
Antimicrobial Agents and Chemotherapy Jun 1985The biochemical mechanism of resistance to kanamycin, viomycin, and rifampin in five clinical isolates of Mycobacterium tuberculosis was studied. Resistance to viomycin...
The biochemical mechanism of resistance to kanamycin, viomycin, and rifampin in five clinical isolates of Mycobacterium tuberculosis was studied. Resistance to viomycin and kanamycin was attributed to altered ribosomes, whereas resistance to rifampin was attributed to an alteration of RNA polymerase. Ribosomal resistance was, however, not the only way of expressing resistance to viomycin and kanamycin.
Topics: Anti-Bacterial Agents; DNA-Directed RNA Polymerases; Drug Resistance, Microbial; Humans; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Peptides; Poly U; Ribosomes
PubMed: 3927838
DOI: 10.1128/AAC.27.6.921 -
The Journal of Antibiotics Feb 1985
Comparative Study
Topics: Bacterial Proteins; Cell-Free System; Dialysis; Drug Resistance; Enviomycin; Escherichia coli; Mutagenicity Tests; Mycobacterium; Protein Binding; Ribosomal Proteins; Ribosomes; Viomycin
PubMed: 2987173
DOI: 10.7164/antibiotics.38.266 -
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 -
Antimicrobial Agents and Chemotherapy Dec 1984The in vitro susceptibility of three strains of an unclassified Mycobacterium sp., isolated from three patients with Crohn's disease, to 23 antimicrobial agents was...
The in vitro susceptibility of three strains of an unclassified Mycobacterium sp., isolated from three patients with Crohn's disease, to 23 antimicrobial agents was determined by a modified broth dilution method with 7H9 broth containing oleic acid-albumin-dextrose-catalase, Tween 80, and mycobactin J. All three strains were susceptible to streptomycin, viomycin, rifampin, clofazimine, cefazolin, amikacin, and kanamycin and resistant to p-aminosalicylic acid, cycloserine, 2-thiophenecarboxylic acid hydrazide, trimethoprim, diaminodiphenylsulfone, sulfamethoxazole, sulfadimethoxine, polymyxin B, metronidazole, neomycin, and carbenicillin. Variable results between strains were encountered with ethambutol, ethionamide, capreomycin, amoxicillin, and cephalothin.
Topics: Adolescent; Anti-Bacterial Agents; Child; Crohn Disease; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Mycobacterium
PubMed: 6524906
DOI: 10.1128/AAC.26.6.930 -
The Journal of Antibiotics Dec 1983Palmitoyltuberactinamine N (Pal-Tua N) and di-beta-lysylcapreomycin IIA (di-beta-Lys-Cpm IIA), which are synthetic derivatives of the antituberculous agent... (Comparative Study)
Comparative Study
Palmitoyltuberactinamine N (Pal-Tua N) and di-beta-lysylcapreomycin IIA (di-beta-Lys-Cpm IIA), which are synthetic derivatives of the antituberculous agent tuberactinomycin (Tum) and capreomycin (Cpm) respectively, were tested for anti-bacterial activity. Pal-Tua N inhibited not only tuberactinomycin-resistant Mycobacterium smegmatis but also Escherichia coli, Corynebacterium diphtheriae, Staphylococcus aureus, Streptococcus pyogenes, although it has lost activity against Mycobacterium tuberculosis. Di-beta-Lys-Cpm IIA inhibited the growth of laboratory-derived Tum-resistant M. smegmatis and M. tuberculosis as well as Tum-resistant M. tuberculosis from patients with one exceptional case.
Topics: Anti-Bacterial Agents; Bacteria; Capreomycin; DNA-Directed RNA Polymerases; Enviomycin; Microbial Sensitivity Tests; Mycobacterium; Ribosomes; Species Specificity; Structure-Activity Relationship; Transcription, Genetic; Viomycin
PubMed: 6198315
DOI: 10.7164/antibiotics.36.1729 -
FEBS Letters Jun 198370 S ribosomes were programmed with initiator tRNA and messenger oligonucleotides AUG(U)n and AUG(C)n, where n = 1, 2 or 3. The binding of the ternary complexes...
70 S ribosomes were programmed with initiator tRNA and messenger oligonucleotides AUG(U)n and AUG(C)n, where n = 1, 2 or 3. The binding of the ternary complexes [Phe-tRNA X EF-Tu X GTP] and [Pro-tRNA X EF-Tu X GTP] to the programmed ribosomes was studied. If codon-anticodon interaction is restricted to only one basepair, the ternary complex leaves the ribosome before GTP hydrolysis. Two basepairs allow hydrolysis of GTP, but the aminoacyl-tRNA dissociates and is recycled, resulting in wastage of GTP. Three basepairs result in apparently stable binding of aminoacyl-tRNA to the ribosome. The antibiotic sparsomycin weakens the binding by an amount roughly equivalent to one messenger base, while viomycin has the reverse effect.
Topics: Antibiotics, Antineoplastic; Binding Sites; Chemical Phenomena; Chemistry; Codon; Genetic Code; Guanosine Triphosphate; Hydrolysis; RNA, Messenger; RNA, Transfer, Amino Acyl; Ribosomes; Sparsomycin; Viomycin
PubMed: 6303858
DOI: 10.1016/0014-5793(83)80519-5 -
The Journal of Antibiotics Feb 1983
Topics: Capreomycin; Drug Resistance, Microbial; Mycobacterium; Viomycin
PubMed: 6187721
DOI: 10.7164/antibiotics.36.197