Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Conformational transitions in several individual tRNAs (tRNAMetf, tRNAPhe from E. coli, tRNAVal1, tRNASer, tRNAPhe from yeast) have been studied under various environmental conditions. The binding isotherms studies for dyes-tRNA complexes exhibited similarities in conformational states of all tRNAs investigated at low ionic strength (0.01 M NaCl). By contrast, at high ionic strength (0.4 M NaCl or 2 X 10(-4) M Mg2+) a marked difference is found in structural features of tRNAMetf as compared with other tRNAs used. The tRNAMetf is the only tRNA species that does not reveal the strong type of complexes with ethidium bromide, acriflavine and acridine orange.
Mol Biol Rep 1976 Jul
PMID:Conformational peculiarities of tRNAMetf from E. coli as revealed by fluorescent methods. 78 33

The chemically reactive analog of U-G-A, 5'-(4-(Bromo-[2-14C] acetamido) phenylphospho) - uridylyl-(3'-5') - guanylyl-(3'-5') adenosine has a 20 fold lower affinity to 70S ribosomes than the corresponding analog of A-U-G though the U-G-A analog also preferentially reacts with protein S18 of 70S ribosomes. This reaction programs ribosomes for EF-T dependent Trp-tRNATrp-suIII binding. Therefore, it is concluded that this protein is part of the A'-site of the ribosomal codon binding site. Reaction of the U-G-A analog with 30S subunits lead to a predominant crosslinking of U-G-A to proteins S4 and S18. In contrast, a comparable reaction of the A-U-G analog with 30S subunits lead to a predominant crosslinking of A-U-G to proteins S4 and S12 (Pongs, O., Stoffler, G.A., Lanka, E., (1975) J. Mol. Biol. 99, 301). Since protein S12 is located at the 'P' site of the ribosomal codon binding site, it is proposed that the U-G-A analog does not bind at this site.
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PMID:Comparison of the reactions of chemically reactive analogs of U-G-A and of A-U-G with ribosomes of Escherichia coli. 78 25

A mutant of Saccharomyces cerevisiae has been isolated which, though exhibiting a normal response to nuclear genetic damage by ultraviolet light (UV), is more sensitive than its wild type specifically in the production of the cytoplasmic (rho-) mutation by this agent. Some of the features of this mutation which has been designated uvsrho 5 are: i) The mutation is recessive, it exhibits a Mendelian, and hence presumably nuclear, pattern of segregation, but manifests its effects specifically and pleiotropically on mitochondrial functions. ii) Mutant cells resemble their wild type parents in a) growth characteristics on glucose; b) in their UV induced dose response to lethality or nuclear mutation and c) the ability of their mitochondrial genome, upon mating with appropriate testers, of transmitting and recombining various markers, albeit with enhanced efficiency. Similarly, d) they are able to modulate the expression of mitochondrial mutagenesis by ethidium bromide. Thus their mitochondrial DNA appears genetically as competent as that of the wild type. iii) Mutant cells differ from their wild type parents in a) growth characteristics on glycerol; b) susceptibility to induction of the mitochondrial (rho-) mutation by various mutagens, in that the rate of spontaneous mutation is slightly and that by UV is significantly enhanced, whild that by ethidium bromide is greatly diminished. Conversely, c) modulating influences resulting in the repair of initial damage are diminished fro UV and stimulated in the case of Berenil. iv) The amount of mitochondrial DNA per cell appears elevated in the mutant, relative to wild type, and its rate of degradation subsequent to a mutagenic exposure to either UV or ethidium bromide is diminished. v) A self-consistent scheme to account for this and all other information so far available for the induction and modulation of the (rho-) mutation is presented. In a previous study it was shown that some nuclear mutants of Saccharomyces cerevisiae, more sensitive to lethal damage induced by ultraviolet light (rad) than their parent wild type (RAD), also exhibit a concomitant modification in sensitivity to both nuclear and cytoplasmic genetic damage (Moustacchi, 1971). However, another class of rad mutants respond to the induction of the cytoplasmic "petite" also designated as rho- (or rho-) mutation by UV in a manner indistinguishable from that of the RAD strain. One possible interpretation of this last observation is that some of the steps in the expression of the UV damage on mitochondrial (mt)DNA may be governed by other nuclear and cytoplasmic genetic determinants, the products of which may then act specifically on mitochondrial lesions. If this assumption is correct, it should be possible to find mutants with a normal response to nuclear damage but specifically UV-sensitive towards induction of (rho-)...
Mol Gen Genet 1976 Nov 17
PMID:A novel class of Saccharomyces cerevisiae mutants specifically UV-sensitive to "petite" induction. 79 62

A few eryR mutants independently isolated from K. lactis CBS 2360 display a conditional lethal phenotype at the temperature of 36 degrees C. In addition to drug resistance, also conditional lethality shows a non-Mendelian pattern of inheritance and is affected by exposure of the cells to Ethidium Bromide, indicating that in this yeast mitochondrial DNA controls cell viability. The results obtained from biochemical analysis suggest that the cellular functions in which are involved the gene products of the mitochondrial mutants analized are cytoplasmic protein and RNA syntheses.
Mol Gen Genet 1977 Jan 18
PMID:Dependence of cytoplasmic on mitochondrial protein synthesis in K. lactis CBS 2360. II. Genetic studies. 84 Feb 24

1. A quantitative radioimmunoassay was developed for the measurement of nanogram amounts of Tamm-Horsfall (TH) glycoprotein in the presence of serum proteins at concentrations above 30 mg/ml. 2. Specific anti-(TH-glycoprotein) antibodies were labelled with 125I and these were usable for a period of 8 weeks. 3. Agarose beads (Sepharose 4B), to which TH-glycoprotein had been coupled via cyanogen bromide activation of the Sepharose, were used as the solid phase in the assay. This proved stable upon storage at 4 degrees C for periods in excess of 4 months. 4. The dissociation of the glycoprotein in the presence of serum proteins that was necessary for quantification was achieved by subjecting the sample to ultrasonication. 5. Assays conducted on a small sample of normal serum produced evidence that normal serum contained amounts (50-180 ng/ml) of a substance that reacted similarly to TH-glycoprotein in the assay procedure and in a series of experiments conducted to confirm the presence of this substance in human serum.
Clin Sci Mol Med 1977 Feb
PMID:The development of a radioimmunoassay procedure for the estimation of Tamm-Horsfall glycoprotein in human serum. 84 51

Treatment of growing cultures of Mycobacterium smegmatis with alkylating agents (methyl methanesulphonate, ethyl methanesulphonate, nitrogen mustard, or mitomycin C) or with ultraviolet light resulted in enhanced specific activities of a DNA polymerase and of an ATP-dependent deoxyribonuclease. Similar results had previously been obtained with hydroxyurea and with iron limitation. The three of these treatments which were tested (methyl methanesulphonate, mitomycin C and hydroxyurea) produced strand breaks or alkali-labile regions in the DNA of this organism. The increased enzyme activities could be prevented by simultaneous treatment with inhibitors of protein synthesis. In contrast, treatment of the cultures with intercalating agents (ethidium bromide, acridine orange, or proflavine), 5-fluorouracil, caffeine, or nalidixic acid, inhibited DNA synthesis without increasing the enzyme activities. These treatments did not produce strand breaks in the DNA of this organism. The results support the hypothesis that, in M. smegmatis, damage to DNA induces increased synthesis of enzymes associated with DNA repair.
Mol Gen Genet 1977 Feb 15
PMID:Increased DNA polymerase and ATP-dependent deoxyribonuclease activities following DNA damages in mycobacterium smegmatis. 84 85

(1) Two viper cells lines were investigated, one which harbors IMV in the mitochondria (VSW cells) and one without detectable IMV (VH3 cells). (2) The size of closed circular mtDNA molecules from both VSW and VH3 cells was found to be significantly greater (5.4 to 5.6 micron) than the contour lengths of typical mammalian cells (4.8 to 5.2 micron). (3) A small percentage of mini-circles ranging in size from 0.1 to 0.6 micron was observed to band with closed circular mtDNA from both cell lines. Minicircles were especially abundant in VH3 cells. (4) MtDNA from VSW cells contained 34.1% dimers plus oligomers (10.2% oligomers), whereas VH3 cells had only 14.8% dimeric and oligomeric forms (5.4% oligomers). (5) Treatment of VSW cells with 1 microng/ml ethidium bromide for 48 hours resulted in an increased incidence of IMV (IMV in 15% of mitochondrial sections) as compared with untreated VSW cells (IMV in 3% of mitochondrial sections).
Mol Cell Biochem 1977 Feb 04
PMID:Studies of mitochondria and mitochondrial DNA extracted from organelles harboring an intramitochondrial virus. 85 28

A procedure is described for demonstrating plasmid DNA and its molecular weight, based on rate zonal centrifugation of unlabelled DNA in neutral sucrose gradients containing a low concentration of ethidium bromide. Each DNA species is then visualized as a discrete fluorescent band when the centrifuge tube is illuminated with ultra-violet light. Plasmids exist as closed circular and as relaxed circular molecules, which sediment separately, but during preparation of lysates, closed circular molecules are nicked so that each plasmid forms only a single band of relaxed circles within the gradient.
Mol Gen Genet 1977 Mar 07
PMID:Rapid screening for plasmid DNA. 87 23

The onset of senescence, i.e. decrease of growth rate followed by cellular death, is prevented when inhibitors of mitochondrial function (ethidium-bromide, streptomycin, tiamulin) are present in the culture medium. If mycelia are transferred to a medium not containing one of these substances, senescence occurs after the usual time interval (30 d at 26 degrees C). Inhibitors of cytoplasmic protein synthesis such as emetine and cycloheximide have no effect in preventing senescence.
Mol Gen Genet 1977 May 20
PMID:Inhibitors of mitochondrial function prevent senescence in the ascomycete Podosprora anserina. 88 69

Ovalbumin messenger RNA was purified from hen oviduct by immunoprecipitation of polysomes and oligo(dT)-cellulose chromatography. Two steps were introduced to improve the separation of mRNA and rRNA by oligo(dT)-cellulose. First, aggregates of mRNA and rRNA were dissociated by heating at 65degrees for 10 min before chromatography. Second, elution of the mRNA was achieved by stepwise increases in temperature rather than by lowering the ionic strength. Ovalbumin mRNA activity was eluted primarily in RNA fractions eluting between 45degrees and 55degrees. Polyacrylamide gel electrophoresis indicated that the ovalbumin mRNA thus obtained was essentiallyyy free of rRNA. The poly(A) content of various thermally eluted fractions was assayed by two methods. In the first (Favre, A., Bertazzoni, V., Berns, A.J.M., and Bloemendal, H. (1974) Biochem. Biophys. Res. Commun. 56, 273-280), the increase in fluorescence intensity of bound ethidium bromide was used to follow the formation of double-stranded RNA during titration of the mRNA with poly(U). In the second (Bishop, J. O., Rosbash, M., and Evans, D. (1974) J. Mol. Biol. 85, 75-86), poly(A) content was derived from the radioactivity remaining acid-insoluble after annealing mRNA fractions with [3H]poly(U) and treating with ribonuclease A. Both methods indicated that ovalbumin mRNA fractions eluting at higher temperatures contained greater amounts of poly(A). Values ranged from 44 to 248 mol of AMP/mol of mRNA, assuming 2200 total nucleotide residues for ovalbumin mRNA (Shapiro, D. J., and Schimke, R. T. (1975) J. Biol. Chem. 250, 1759-1764). Translational specific activities in a rabbit reticulocyte lysate system were essentiall constant for all fractions. From the binding of ethidium bromide it could be estimated that approximately 50% of the nucleotide residues in ovalbumin mRNA are base-paired.
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PMID:Ovalbumin messenger ribonucleic acid. Purification and fractionation on the basis of polyadenylate content by thermal elution from oligodeoxythymidylate-cellulose. 117 62


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