Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.7 (DNA polymerase)
17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of large, possibly complete, complementary DNA (cDNA) copies of poliovirus RNA by avian myeloblastosis virus DNA polymerase is described. The cDNA consists of two size classes, the larger of which is approximately 7500 nucleotides. In the presence of excess deoxynucleoside triphosphates, ribonucleoside triphosphates, or sodium pyrophosphate, only the larger material is obtained. Yields of the large cDNA are 50-75% of the input RNA.
...
PMID:Synthesis of extensive, possibly complete, DNA copies of poliovirus RNA in high yields and at high specific activities. 5 25

It has been demonstrated that malignant diseases of the gastrointestinal tract and lung in humans possess three characteristics invariably found in ribonucleic acid tumor viruses: the presence of a ribonucleic acid directed deoxyribonucleic acid polymerase, reverse transcriptase; a high molecular weight ribonucleic acid with a sedimentation coefficient of 70 Svedberg units, and particulate elements with densities of 1.16 to 1.18 grams per milliliter sucrose gradient. Twelve of 17 carcinomas of the colon, three of five carcinomas of the stomach, all three carcinomas of the rectum and seven of ten carcinomas of the lung displayed detectable evidence of these viral-like entities. None of the corresponding normal tissues had positive reactions.
...
PMID:Biochemical evidences for ribonucleic acid viral-like characteristics in malignant diseases of gastrointestinal tract and lung in humans. 5 52

The association of avian myeloblastosis virus (AMV) DNA polymerase with polynucleotide templates during catalysis has been studied. During the course of polymerization, different template-primer complexes were added and the ability of the enzyme to switch from one polynucleotide template to another was determined. At 37 degrees C as well as at 4 degrees C, the polymerase is able to switch from certain template-primer complexes to others. For example, the addition of poly(A)-oligo(dT) during the course of synthesis with poly(C)-oligo(dG) results in the immediate cessation of dGMP polymerization and the start of dTMP polymerization without any lag. Early during the course of polymerization, the size of the product, as determined by alkaline sucrose gradient centrifugation, is, in part, a function of the ratio of the template-primer complex to the enzyme. These cumulative experiments indicate that catalysis on polynucleotide templates with avian myeloblastosis virus DNA polymerase under the conditions tested is not processive in a classical sense. Similar to cellular DNA polymerases the enzyme can shift from one template-primer to another. Using autoradiography after gel electrophoresis to estimate the product size, it can be calculated that the enzyme switches from one template to another within 0.25 min at 37 degrees C which corresponds to the incorporation of greater than 25 nucleotides. At 4 degrees C, switching can be calculated to occur in less than three nucleotide addition steps. Thus, with certain homopolymers, conditions can be found by which AMV DNA polymerase can switch from one template-primer complex to another, perhaps after each nucleotide addition step.
...
PMID:On the association of reverse transcriptase with polynucleotide templates during catalysis. 6 Jan 29

Full-length, single-stranded rabbit globin cDNA, synthesized by AMV reverse transcriptase, apparently contains a small double-stranded sequence (hairpin) at the 3' terminus. This cDNA can serve as template-primer for E. coli DNA polymerase I, which synthesizes a strand complementary to the cDNA and covalently bound to it. The loop connecting the two strands can be cut by S1 nuclease. Reassociation, hybridization, and restriction endonuclease studies, as well as electrophoretic analyses, indicate that the sequential actions of reverse transcriptase, DNA polymerase 1, and S1 nuclease generate full-length, double-stranded synthetic globin genes.
...
PMID:Enzymatic in vitro synthesis of globin genes. 6 Jan 78

The effects of Mg++, Mn++, and KCl addition, individually and in combination, on the rate of DNA- and RNA-primed DNA synthesis by avian myeloblastosis virus DNA polymerase (reverse transcriptase) using a variety of natural and synthetic template-primer combinations were examined. Optimal divalent cation concentrations were found to vary by as much as 10-fold depending upon the template-primer used to direct synthesis. Addition of KCl to reaction mixtures containing optimal divalent cation concentrations produced stimulation or inhibition of DNA synthesis which was also template-specific. DNA synthesis on the modified template poly (2'-0-methylcytidylate) was uniquely stimulated by combinations of divalent cations. With Mg++ as divalent cation, deviations from classical Michaelis-Menten kinetics of substrate saturation were observed with all template-primers tested.
...
PMID:Observations on template-specific conditions for DNA synthesis by avian myeloblastosis virus DNA polymerase. 6 Jul 40

The sulfated glycosaminoglycans chondroitin 4-sulfate, chondroitin 6-sulfate, keratan sulfate, dermatan sulfate, heparin, and glycosaminoglycan polysulfate are competitive inhibitors of the DNA-dependent RNA polymerase, the DNA-dependent RNA polymerase and the RNA-dependent DNA polymerase (reverse transcriptase). The unsulfated glycosaminoglycans chondroitin and hyaluronate are without any influence on the synthesis of DNA and RNA. The strongest inhibitor is a glycosaminoglycan polysulfate with four sulfate groups per disaccharide unit. It has the following inhibitor constants: DNA polymerase, Ki = 1.5 X 10(-6) M; RNA polymerase, Ki = 0.9 X 10(-6) M; reverse transcriptase, Ki = 1.1 X 10(-6) M. The inhibition is closely correlated to the degree of sulfation of the glycosaminoglycans. There is a relationship between the sulfate/hexosamine ratio and the degree of inhibition. The inhibition of the DNA and RNA synthesizing enzymes by sulfated glycosaminoglycans depends on the nature of the template. With double-stranded DNA as template, inhibition occurs only when sulfated glycosaminoglycans are added before or shortly after (30 s) initiation of the synthesis. There is no inhibition if the inhibitors are added after the onset of the synthesis. On the other hand, with a single-stranded template synthesis was blocked completely at each phase of reaction.
...
PMID:Interactions of glycosaminoglycans with DNA and RNA synthesizing enzymes in vitro. 6 Nov 58

The properties of an RNA-dependent DNA polymerase (an RNA-dependent DNA nucleotidyltransferase), which occurs ubiquitously in the allantoic fluid of uninfected, leukosis-virus-free eggs, are described. It is shown that the enzyme can synthesize faithful transcripts from natural RNA (globin mRNA). By biochemical and immunological methods, the enzyme can be clearly distinguished from the reverse transcriptases of the known chicken RNA tumor viruses and therefore seems to be a member of a so far unknown class of chicken polymerases.
...
PMID:An RNA-dependent DNA polymerase, different from the known viral reverse transcriptases, in the chicken system. 6 87

The stability of Rauscher leukemia virus (RLV) was investigated under certain laboratory conditions. The half life of the virus at 37 degrees was 7 hr, and considerably longer at lower temperatures. RNA dependent DNA polymerase activity was more stable than infectivity at all temperatures. Air dried virus had a half life of approximately 1 hr, but was rapidly inactivated by uv light or 70% alcohol.
...
PMID:Stability of Rauscher leukemia virus under certain laboratory conditions. 6 90

The alpha subunit of the avian myeloblastosis virus DNA polymerase could be readily purified to near homogeneity using a polyuridylic acid-Sepharose column chromatography step.
...
PMID:Purification of the alpha subunit of avian myeloblastosis virus DNA polymerase by polyuridylic acid-sepharose. 6 57

The reverse transcriptase (RNA-directed DNA nucleotidyltransferase) from avian myeloblastosis virus is able to make an extensive, possibly complete, complementary DNA copy of intact poliovirus RNA. In the presence of high concentrations of deoxyribonucleoside triphosphates, ribonucleoside triphosphates, or sodium pyrophosphate, this DNA is the only species produced. Without these additives, however, a second size class of DNA is also synthesized. This material has a sedimentation coefficient between roughly 4 and 10 S and is produced later in the reaction, largely after synthesis of the larger complementary DNA has ceased. The smaller DNA consists primarily of material anticomplementary to the RNA template and contains a faithful and uniform representation of the viral sequences. It most likely arises by transcription of the larger DNA species.
...
PMID:Anticomplementary nature of smaller DNA produced during synthesis of extensive DNA copies of poliovirus RNA. 6 59


<< Previous 1 2 3 4 5 6 7 8 9 10

---