Showing papers on "RNA-dependent RNA polymerase published in 1969"
TL;DR: A protein component usually associated with RNA polymerase can be separated from the enzyme by chromatography on phosphocellulose, and the polymerase is unable to transcribe T4 DNA unless this factor is added back.
Abstract: A protein component usually associated with RNA polymerase can be separated from the enzyme by chromatography on phosphocellulose. The polymerase is unable to transcribe T4 DNA unless this factor is added back.
917 citations
TL;DR: Three distinct RNA polymerase activities have been isolated from developing sea urchin embryos, and in rat liver nuclei there are two RNA polymerases activities.
Abstract: Three distinct RNA polymerase activities have been isolated from developing sea urchin embryos. In rat liver nuclei there are two RNA polymerase activities. One polymerase (I) is probably localized in the nucleolus and one (II) in the nucleoplasm.
895 citations
TL;DR: A new protein has been isolated from E. coli which causes specific termination and release of RNA during synthesis in vitro and has been given the name ρ-factor.
Abstract: A new protein has been isolated from E. coli which causes specific termination and release of RNA during synthesis in vitro. It has been given the name ρ-factor.
739 citations
TL;DR: The RNA polymerase σ factor is required for the initiation of RNA synthesis and may be re-used by another polymerase molecule to initiate a new RNA chain.
Abstract: The RNA polymerase σ factor is required for the initiation of RNA synthesis. After initiation σ is released from the polymerase-factor complex and from the DNA template, and may then be re-used by another polymerase molecule to initiate a new RNA chain.
373 citations
TL;DR: The enzyme present in reovirus particles is thus a novel RNA transcriptase which transcribes double-stranded RNA in a manner analogous to that by which DNA-dependent RNA polymerase transcribes DNA.
236 citations
TL;DR: If prepared free of the hybrid-degrading enzyme, RNA polymerase from calf thymus shows a fivefold increase in activity on denatured DNA as compared to native DNA.
Abstract: An enzyme present in extracts from calf thymus degrades specifically the RNA moiety of DNA-RNA hybrids. Other nucleic acids, such as single- or double-stranded DNA and single- or double-stranded RNA, are not affected to a comparable degree. If prepared free of the hybrid-degrading enzyme, RNA polymerase from calf thymus shows a fivefold increase in activity on denatured DNA as compared to native DNA.
224 citations
TL;DR: Two major virus-specific RNA species were resolved in the cytoplasm of cultured human (KB) cells early after infection with adenovirus (Ad) type 2 and constitute a single class of RNA molecules whose transcription is not dependent upon virus specific early proteins.
224 citations
TL;DR: The phosphocellulose component of RNA polymerase binds the first nucleotide when synthesis of an RNA chain is initiated.
Abstract: The phosphocellulose component of RNA polymerase binds the first nucleotide when synthesis of an RNA chain is initiated
219 citations
TL;DR: In this article, the number of 4, 18 and 26 s RNA cistrons present in purified nuclear and mitochondrial DNA of Saccharomyces cerevisiae has been determined and the significance of these findings to the continuous synthesis of ribosomal RNA during the cell cycle of yeast is discussed.
218 citations
211 citations
TL;DR: Double-stranded RNA has been isolated from chick cells and chick cells infected with vaccinia virus and induces production of interferon.
Abstract: Double-stranded RNA has been isolated from chick cells and chick cells infected with vaccinia virus. The double-stranded vaccinia virus RNA induces production of interferon.
TL;DR: RNA polymerase from sporulating cells of Bacillus subtilis fails to transcribe phage ϕe DNA in vitro while RNA polymer enzyme from vegetative cells is active with the same template.
Abstract: RNA polymerase from sporulating cells of Bacillus subtilis fails to transcribe phage ϕe DNA in vitro while RNA polymerase from vegetative cells is active with the same template.
TL;DR: The transition of suspension cultures of Novikoff rat hepatoma cells from the exponential to the stationary phase is accompanied by decreases of over 90% in the rates of synthesis of RNA, DNA and protein, and a disaggregation of the polyribosomes with a concomitant accumulation of 80 S and 110 S ribosomal structures.
Abstract: The transition of suspension cultures of Novikoff rat hepatoma cells from the exponential to the stationary phase is accompanied by decreases of over 90% in the rates of synthesis of RNA, DNA and protein, a 90% loss of the apparent DNA-dependent RNA polymerase activity of the cells, and a disaggregation of the polyribosomes with a concomitant accumulation of 80 S and 110 S ribosomal structures. The cells also attain a minimum content of DNA, RNA and protein and a minimum size. Upon dilution of stationary phase cultures with fresh medium, the rate of protein synthesis begins to increase immediately and this correlates with a rapid reformation of the polyribosomes. The initial re-formation of polyribosomes is little affected by the presence of actinomycin D. RNA polymerase activity also begins to increase immediately after dilution and an increase in rate of RNA synthesis becomes apparent shortly thereafter. The increase in polymerase activity is inhibited by treating the cells with puromycin or actidione. Cell division commences only 9–13 hours after dilution and the rate of DNA synthesis begins to increase about midway through the lag period. During the lag period the average cellular content of protein increases about 80% and that of RNA and DNA about 30%. These increases are accompanied by a marked increase in the average size of the cells.
Upon continued incubation of stationary phase cultures, the cells become irreversibly damaged physiologically before gross morphological damage becomes apparent. The irreversible physiological damage is recognized by the fact that the cells fail to recover when suspended in fresh medium.
TL;DR: The σ factor of E. coli RNA polymerase selectively promotes transcription of T4 phage pre-early genes and residual activity of the minimal enzyme on T4 DNA is caused by random initiation on both strands of the entire T4DNA molecule.
Abstract: The σ factor of E. coli RNA polymerase selectively promotes transcription of T4 phage pre-early genes. The residual activity of the minimal enzyme on T4 DNA is caused by random initiation on both strands of the entire T4 DNA molecule.
TL;DR: An RNA polymerase factor analogous to the E. coli σ factor has been isolated from T4-infected cells and it is proposed that this factor direct the transcription of different portions of the T4 genome.
Abstract: An RNA polymerase factor analogous to the E. coli σ factor has been isolated from T4-infected cells. The σ factor and the T4 factor direct the transcription of different portions of the T4 genome.
TL;DR: Poliovirus RNA and proteins are synthesized in association with distinct membranous structures that were separated by means of Isopycnic centrifugation of cytoplasmic extracts in discontinuous sucrose-density gradients.
Abstract: Poliovirus RNA and proteins are synthesized in association with distinct membranous structures that were separated by means of Isopycnic centrifugation of cytoplasmic extracts in discontinuous sucrose-density gradients. Viral RNA is replicated in a structure that contains rapidly labeled replicative intermediate RNA and viral RNA polymerase associated with the smooth membrane fraction. In sucrose gradients this viral RNA replication complex is distributed at densities in the range of 1.12 to 1.18 grams per cubic centimeter. Viral proteins are synthesized on polyribosomes bound to membranes and sediment with polyribosomes at densities of less than 1.25 grams per cubic centimeter.
TL;DR: The effect of rifampin, an inhibitor of bacterial DNA-dependent RNA polymerase, was studied in Chlamydomonas reinhardi and it was shown that chloroplast-located, but not nuclear, DNA- dependentRNA polymerase is inhibited by this drug.
Abstract: The effect of rifampin, an inhibitor of bacterial DNA-dependent RNA polymerase, was studied in Chlamydomonas reinhardi. It was shown, in vivo and in vitro, that chloroplast-located, but not nuclear, DNA-dependent RNA polymerase is inhibited by this drug. The inhibition of chloroplast RNA polymerase results in the inhibition of chloroplast rRNA synthesis, and thus in the loss of chloroplast ribosomes. The ability to carry out photosynthesis is also lost after prolonged heterotrophic growth in the presence of rifampin, but cell division and chloroplast replication are not affected. It is proposed that chloroplast DNA contains information for chloroplast rRNA, but this DNA does not have the information for chloroplast DNA polymerase. Moreover, the DNA polymerase is not synthesized on chloroplast ribosomes.
TL;DR: The protein specified by the T7 phage gene I co-purifies with the RNA polymerase from phage infected E. coli and determines the fidelity of template strand selection during in vitro RNA synthesis with T7 DNA as template.
Abstract: The protein specified by the T7 phage gene I co-purifies with the RNA polymerase from phage infected E. coli. It also determines the fidelity of template strand selection during in vitro RNA synthesis with T7 DNA as template.
TL;DR: It is reported that streptolydigin inhibits chain elongation by E. coli RNA polymerase as was found by Siddhikol et al.4 and that, as is the case of rifampicin resistance1,2, the “core” enzyme (the α2ββ′ structure which itself possesses enzymatic activity) is modified in the resistant mutant.
Abstract: THE RNA polymerase of Escherichia coli consists of two small subunits α, two larger subunits β and β′, and one subunit σ which aids initiation1. A question relevant to control of polymerase synthesis is whether genes coding for the various subunits are contiguous. Both rifampicin resistant RNA polymerase and streptovaricin resistant RNA polymerase map near the argH locus2,3. Here I report that (a) streptolydigin inhibits chain elongation by E. coli RNA polymerase as was found by Siddhikol et al.4 for the polymerase of B. megaterium, (b) mutants altering the polymerase to streptolydigin resistance also map near argH, and (c) that, as is the case of rifampicin resistance1,2, the “core” enzyme (the α2ββ′ structure which itself possesses enzymatic activity) is modified in the resistant mutant.
TL;DR: It is indicated that T4 infection induces an alteration in host ribosomes which restricts the translation of host and other T4-unrelated template RNAs but permits normal translation of T4 RNA.
Abstract: The present studies indicate that T4 infection induces an alteration in host ribosomes which restricts the translation of host and other T4-unrelated template RNAs but permits normal translation of T4 RNA A heat-labile factor has been isolated from T4-infected cell ribosomes which, when combined with normal cell ribosomes, confers upon the latter the property of selective T4 template RNA translation
TL;DR: The results suggest that auxin plus the protein increase the rate of RNA synthesis by making an increased portion of the genome available for transcription.
Abstract: The increased rate of RNA synthesis by target cells caused by the plant hormone auxin has been studied as an example of hormonal regulation of transcription. The hormone does not interact directly with chromatin but requires a protein mediator. In the presence of this mediator, auxin increases the rate of RNA synthesis both by isolated plant nuclei and by isolated chromatin. This increased rate of RNA synthesis occurs even in the presence of saturating amounts of RNA polymerase. The hormone and protein do not affect the rate of RNA synthesis if pure DNA is used as the template. The results suggest that auxin plus the protein increase the rate of RNA synthesis by making an increased portion of the genome available for transcription.
TL;DR: The “modified” DNA-dependent RNA polymerase, isolated from E. coli cells infected with phage T4 and unable to transcribe T4 DNA, can be activated by addition of a protein factor normally associated with RNA polymer enzyme from uninfected cells.
TL;DR: The RNA found in Qβ phage-infected Escherichia coli was highly resistant to RNase although nearest-neighbor analysis did not indicate that a completely double-stranded structure was being replicated.
TL;DR: These two communications present results which suggest that the transcription of the entire genome of phages T4 and SPO1 requires host RNA polymerase, or at least those components of it which are sensitive to rifamycin.
Abstract: These two communications present results which suggest that the transcription of the entire genome of phages T4 and SPO1 requires host RNA polymerase, or at least those components of it which are sensitive to rifamycin
TL;DR: It is concluded from this experiment that the replicative intermediate is the precursor to viral RNA.
Abstract: Poliovirus ribonucleic acid (RNA) polymerase crude extracts could be stored frozen in liquid nitrogen without loss of activity or specificity. The major in vitro product of these extracts was viral single-stranded RNA. However, after short periods of incubation with radioactive nucleoside triphosphates, most of the incorporated label was found in replicative intermediate. When excess unlabeled nucleoside triphosphate was added, the label was displaced from the replicative intermediate and accumulated as viral RNA. It is concluded from this experiment that the replicative intermediate is the precursor to viral RNA. In addition, some of the label was chased into double-stranded RNA. The implications of this finding are discussed.
TL;DR: The decrease in the activity of DNA-dependent RNA polymerase in Escherichia coli after infection with bacteriophage T4 is the consequence of a structural change of the polymerase and not of the appearance of an inhibitor.
Abstract: The decrease in the activity of DNA-dependent RNA polymerase in Escherichia coli after infection with bacteriophage T4 is the consequence of a structural change of the polymerase and not of the appearance of an inhibitor. The kinetics of this change were followed using polymerases highly purified at different times after infection (a) by measuring the specific enzymatic activity with T4- and calf thymus DNA as templates and (b) by following the appearance of the modified polymerase-subunit in disc-electrophoresis.
The results allow one to differentiate between two consecutive processes:
1
A very rapid alteration which inactivates the RNA polymerase for T4-DNA, but not for other DNA templates, and which does not require protein synthesis.
2
A structural modification which depends on protein synthesis and leads to a change in one subunit of the polymerase.
As shown by the use of the T4-mutants am BL 292 and am N.134 neither gene 55 nor gene 33, both involved in the transcription of late genes, are participating in the modification reaction.
TL;DR: It is demonstrated that the in vitro template activity of Qβ RNA is not destroyed by removal of the adenylate and a scheme is put forward to account for the presence of 3′-terminal adenosine in the product of replication.
Abstract: Studies with Qβ RNA confirm Kamen's finding, with R17 RNA, that the terminal adenylate is not necessary for infectivity. It is now demonstrated that the in vitro template activity of Qβ RNA is not destroyed by removal of the adenylate and a scheme is put forward to account for the presence of 3′-terminal adenosine in the product of replication.
TL;DR: These studies suggest that the yeast enzyme has a decreased ability to cause localized denaturation of native DNA compared to the E. coli enzyme.
TL;DR: The failure of RNA and polyribonucleotides to reverse the inhibition of RNA synthesis in vitro by histones is due to the dissociation of RNA-histone complexes by the template DNA used in the RNA polymerase assay mixtures.
TL;DR: With increasing amount of fr RNA, the formation of virus-like particles is repressed and another kind of complex is formed containing only a few protein subunits per chain of RNA.