Showing papers on "Primase published in 1970"
TL;DR: Double stranded DNA serves as a template primer for Escherichia coli DNA polymerase when the DNA contains a single strand break (a nick) with a 3'-hydroxyl terminus and the ability of the enzyme to promote hydrolysis and synthesis simultaneously results in the translation of the nick along the DNA duplex in the 5' to 3' direction.
400 citations
TL;DR: An RNA dependent DNA polymerase analogous to that of RNA tumour viruses has been found in lymphoblasts of leukaemic patients but not of normal donors.
Abstract: An RNA dependent DNA polymerase analogous to that of RNA tumour viruses has been found in lymphoblasts of leukaemic patients but not of normal donors. The enzyme can use an RNA template from mammalian cells to synthesize DNA.
240 citations
TL;DR: Six RNA viruses have now been shown to contain DNA polymerase activities directed by single-stranded RNA, double-Stranded RNA and double-stranding DNA, and it is further demonstrated that DNA–RNA hybrids, such as synthetic dC.rG, act as even more effective templates.
Abstract: Six RNA viruses have now been shown to contain DNA polymerase activities directed by single-stranded RNA, double-stranded RNA and double-stranded DNA. It is further demonstrated that DNA–RNA hybrids, such as synthetic dC.rG, act as even more effective templates.
186 citations
TL;DR: The transcription of native circular double-stranded SV40 DNA by Escherichia coli RNA polymerase is asymmetric and the product of the in vitro reaction was used to achieve a high degree of separation of the complementary SV40DNA strands.
112 citations
TL;DR: Viral RNA is the template for the DNA polymerase of the sarcoma-leukaemia viruses: a “natural” RNA-DNA hybrid is formed by annealing viral RNA with the DNA product of theDNA polymerase reaction.
Abstract: Viral RNA is the template for the DNA polymerase of the sarcoma-leukaemia viruses: a “natural” RNA-DNA hybrid is formed by the viral DNA polymerase, and a “synthetic” RNA-DNA hybrid is formed by annealing viral RNA with the DNA product of the DNA polymerase reaction.
95 citations
TL;DR: The enzyme involved in the discontinuous replication of DNA seems not to be the Kornberg polymerase but to be associated with the membrane.
Abstract: The enzyme involved in the discontinuous replication of DNA seems not to be the Kornberg polymerase but to be associated with the membrane.
93 citations
TL;DR: The treatment of native DNA polymerase with subtilisin is reported on under conditions which lead to the cleavage of the enzyme into two separate subunits, one which is associated with exonuclease activity and the other with polymerase activity.
88 citations
TL;DR: RNA tumour viruses contain a DNA-dependent DNA polymerase which preferentially uses either single or double stranded DNA rich in guanosine and cytosine as template.
Abstract: RNA tumour viruses contain a DNA-dependent DNA polymerase which preferentially uses either single or double stranded DNA rich in guanosine and cytosine as template. The virion also contains DNA of similar composition as well as A+T rich DNA.
85 citations
TL;DR: Mitochondrial DNA polymerase from Saccharomyces cerevisiae was purified 80-to 100-fold with good yield by DEAE-cellulose chromatography of the extract prepared by disruption of highly purified yeast mitochondria as discussed by the authors.
Abstract: Mitochondrial DNA polymerase from Saccharomyces cerevisiae was purified 80-to 100-fold with good yield by DEAE-cellulose chromatography of the extract prepared by disruption of highly purified yeast mitochondria. The enzyme requires all four deoxyribonucleoside triphosphates, Mg++ and DNA for activity. The optimal Mg++ concentration is 50 mM. Different DNAs, in native as well as denatured or “activated” form, serve as template and primer. The preference for denatured over native DNA and the effective promotion of DNA synthesis by mitochondrial DNA is of special interest. Mitochondria from a cytoplasmic “petite” mutant also contain a DNA polymerase which can be solubilized and purified like the enzyme from wild type yeast. Identical properties were found for the polymerases from normal and mutant mitochondria. On the other hand, characteristic differences between the mitochondrial enzyme and the polymerases A and B obtained from mitochondria-free cell extracts were noted in the behaviour on DEAE-cellulose columns, the optimal Mg++ requirements and the effectiveness of different DNA templates. DNA synthesis with all three enzymes is inhibited in a similar fashion by the intercalating dye acriflavin. The molecular weight of the mitochondrial DNA polymerase from yeast is about 150000.
76 citations
TL;DR: The results lead to the conclusion, that the radiation induced loss of priming activity is mainly due to the formation of a specific lesion in the DNA which stops the process of RNA synthesis along the strand.
60 citations
TL;DR: The polymerase efficiently and faithfully repairs DNA's that contain partially single stranded regions, and replicates a wide variety of naturally occurring DNA's, including double stranded, single stranded, circular, and denatured DNA's.
TL;DR: It is shown that native and denatured DNA form complexes with the oligopeptide‐antibiotic distamycin A and the pronounced inhibition of the incorporation of AMP into RNA in the DNA directed RNA‐polymerase system is due to the interference of the antibiotic with DNA.
TL;DR: During transcription of bacteriophage T4 or T5 DNA in 0.2 M KCl, RNA polymerase is able to terminate the synthesis of RNA chains, dissociate from the DNA template and reinitiate new RNA chains on new DNA templates.
Abstract: During transcription of bacteriophage T4 or T5 DNA in 0.2 M KCl, RNA polymerase is able to terminate the synthesis of RNA chains, dissociate from the DNA template and reinitiate new RNA chains on new DNA templates.
TL;DR: These results show that the quality of the template DNA is a critical consideration in studies on the initiation specificity of RNA polymerase in vitro.
TL;DR: If RNA is synthesized on the chromatin deoxyribonucleoprotein (DNP) template, the chains formed are four to five times shorter than in RNA synthesizedon a DNA template, which correlates with the decrease of the period of elongation.
Abstract: If RNA is synthesized on the chromatin deoxyribonucleoprotein (DNP) template, the chains formed are four to five times shorter than in RNA synthesized on a DNA template. This correlates with the decrease of the period of elongation. After the removal of histone F1 from DNP the RNA chains synthesized are as long as or longer than those formed on free DNA. Histone F1 seems to prevent the movement of RNA polymerase along the DNA.
TL;DR: Differentiation may be controlled by forks in DNA each having a replicatable protein "switch," stable in either a "left" or a "right" configuration, which determines the path through the DNA network taken by RNA polymerases during transcription.
Abstract: Differentiation may be controlled by forks in DNA each having a replicatable protein "switch," stable in either a "left" or a "right" configuration, which determines the path through the DNA network taken by RNA polymerases during transcription The possibility for dedifferentiation exists, but differentiation could be made irreversible by the exertion of a similar control over parts of the paths through the network taken by DNA polymerases The concept of bistable switches at DNA branch points can be used to account for antibody variability
TL;DR: These experiments indicate that, during the course of synthesis, the polymerase reverses its direction of translocation and uses the newly synthesized product as a template for further synthesis, suggesting that the complementary strands of the product DNA are covalently joined by "hairpin loop" structures.
TL;DR: The true DNA replicase system of E. coli may have been identified by assaying DNA synthesis in toluenized bacteria of a temperature sensitive DNA replication mutant.
Abstract: The true DNA replicase system of E. coli may have been identified by assaying DNA synthesis in toluenized bacteria of a temperature sensitive DNA replication mutant.
TL;DR: S and ribosomal RNA's from rat liver can serve as primers for DNA synthesis, using DNA polymerase from E. coli to form a DNA-RNA hybrid.
TL;DR: Results show that RNA polymerase of E. coli can transcribe intact circular mitochondrial DNA, even when the σ factor is inactivated, but that transcription is in part symmetric and with a preference for the non-codogenic strand.
TL;DR: RNA transcription could take place without unwinding the DNA double helix if the RNA chain grows in the wide groove of the DNA by a specific stereochemical interaction between the ribonucleotides and the base pairs of theDNA.
Abstract: RNA transcription could take place without unwinding the DNA double helix if the RNA chain grows in the wide groove of the DNA by a specific stereochemical interaction between the ribonucleotides and the base pairs of the DNA.
TL;DR: Experimental evidence is given for a model in which DNA replicates with the two growing daughter strands covalently linked by a pyrophosphate bridge.
Abstract: Experimental evidence is given for a model in which DNA replicates with the two growing daughter strands covalently linked by a pyrophosphate bridge. The two strands are synthesized synchronously in opposite directions, one 5′ to 3′ and the other 3′ to 5′.
TL;DR: It is shown that this alteration in template specificity is not the direct result of the action of an alkaline endonuclease present in the DNA polymerase preparation.
Abstract: Under standard assay conditions, the replicative DNA polymerase partially purified from rat liver non-histone chromosomal proteins exhibited a marked preference for native DNA over heat-denatured DNA as the template. However, work reported in the present paper demonstrates that this template preference could be reversed by changing the enzyme to template ratio in the assay system. This change in template preference was observed when either the concentration of DNA polymerase or of DNA was varied. Furthermore, it is shown that this alteration in template specificity is not the direct result of the action of an alkaline endonuclease present in the DNA polymerase preparation.
TL;DR: A replicative DNA-nucleotidyl transferase free from detectable endonuclease activity has been partially purified from the nonhistone chromosomal proteins of rat liver.
Journal Article•
TL;DR: Treatment of T7 DNA with hydroxylamine inhibits transcription of this template by Escherichia coli RNA polymerase, and crucial sites on the template may be altered by hydroxyamine because the inhibition in RNA synthesis is not overcome by addition of moreRNA polymerase.
Abstract: Summary Treatment of T7 DNA with hydroxylamine inhibits transcription of this template by Escherichia coli RNA polymerase. At least one effect of hydroxylamine treatment on native T7 DNA is the introduction of single-strand scissions in most of the molecules. Polymerase binding studies suggest that hydroxylaminetreated T7 DNA is somewhat similar to denatured DNA since more RNA polymerase is required for maximal retention on Millipore filters in contrast to untreated DNA. Moreover, crucial sites on the template may be altered by hydroxylamine because the inhibition in RNA synthesis is not overcome by addition of more RNA polymerase.
TL;DR: These experiments suggest that the resistance of the replicative form II DNA to the exonucleolytic activity is a result of the structure of these molecules at their 5'-terminus.
Abstract: The progeny replicative form II DNA isolated from E. coli cells infected with phiX174 is resistant to the exonucleolytic activity associated with E. coli DNA polymerase. A limited endonucleolytic cleavage with micrococcal endonuclease renders the replicative form II molecule susceptible to the exonucleolytic activity associated with the E. coli DNA polymerase. These experiments suggest that the resistance of the replicative form II DNA to the exonucleolytic activity is a result of the structure of these molecules at their 5'-terminus.
Journal Article•
TL;DR: The study of the hybridization behavior of the various RNA products showed that N-RNA, though able to form hybrids with either strand, hybridized with H-DNA to twice as great an extent as with L-DNA.
Abstract: This paper describes the preparation and some of the properties of the RNA specimens synthesized with the aid of the RNA polymerase of E. coli by transcription of the following DNA templates: (a) undenatured B. subtilis DNA (yielding N-RNA); (b) separated strand fractions L and H isolated by chromatography of the denatured DNA on methylated albumin (yielding L-RNA and H-RNA, respectively). The study of the hybridization behavior of the various RNA products showed that N-RNA, though able to form hybrids with either strand, hybridized with H-DNA to twice as great an extent as with L-DNA. The transcripts of the separated L and H fractions exhibited complete specificity with respect to complexing: L-RNA hybridized only with L-DNA, H-RNA only with H-DNA.