Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| translation of genomic avian myeloblastosis virus rna in a cell-free protein synthesis system from rabbit reticulocytes. | reaction conditions suitable for translation of genomic avian myeloblastosis virus rna in micrococcal nuclease-pretreated reticulocyte lysates are described. the products of translation were characterized by immunoprecipitation and gel electrophoresis and compared with virus-specific products formed in host cells. genomic viral rna directed in a cell-free system the synthesis of precursors to viral structural proteins, namely pr76gag and pr180gag,pol. | 1980 | 6104431 |
| cell transformation by avian defective leukaemia viruses. | a comparative study of seven independently isolated defective leukaemia viruses has been carried out. phenotypic analysis of the chicken bone marrow cells transformed in vitro allowed the separation of these seven viruses into three groups based on the differentiation phenotype of the transformed cell. nucleic acid hybridization studies revealed that these seven viruses had acquired cellular sequences. interestingly, these studies also showed that the viruses within the same biological grouping ... | 1980 | 6109301 |
| studies on the structure of avian myeloblastosis virus (amv) rna. i. factors affecting electron microscopic visualization of amv rna. | factors affecting the visualization of single-stranded (ss) avian myeloblastosis virus (amv) rna by the basic protein film technique under strong denaturation conditions were studied. the basic parameters of the electron microscopic picture of ss rna, involving the visibility, concentration and contour lengths of molecules, were found to be significantly dependent on the (1) quality of denaturing components used for full extension of amv rna molecules and (2) spreading and formation of the surfa ... | 1982 | 6124101 |
| studies on the structure of avian myeloblastosis virus (amv) rna. ii. integrity of the rna in dependence on rna isolation and virus propagation. | while sedimentation analysis revealed no basic changes in the sedimentation characteristics of 60-70 s avian myeloblastosis virus (amv) rna isolated under different conditions from two sources, electron microscopy exhibited differences in the length distributions of this rna. based on the length distribution profiles, phenol extraction showed a higher degradation effect in comparison with direct gradient centrifugation of viral lysates. proteinase k appeared to be a more suitable nuclease inhibi ... | 1982 | 6124106 |
| studies on the structure of avian myeloblastosis virus (amv) rna. iii. electron microscopic definition of secondary structure. | the secondary structure of avian myeloblastosis virus (amv) rna was characterized by electron microscopy under moderately denaturing spreading conditions. under denaturation by aqueous 44% formamide or 77% formamide in the presence of salts, partly stretched rna molecules with measurable double-stranded regions were observed. this approach allowed the localization from 5 to 11 regions of preserved secondary structure on amv rna molecules. topographic analysis revealed a nonrandom occurrence of s ... | 1982 | 6124107 |
| electron microscopic studies on the structure of 60-70s rna of avian myeloblastosis virus. | structural properties of the 60-70s rna complex of avian myeloblastosis virus (amv) were analysed in electron microscope after treatment under a set of non-denaturing, gently and strongly denaturing conditions. by selected denaturing conditions, the significant fraction of 60-70s amv rna molecules revealed partially unfolded structures either in a dimer or a more complex form and in a length corresponding to mol. wt. of 5.6 x 10(6). the typical dimers contained a characteristic central structure ... | 1982 | 6132536 |
| structural analysis of rna subunits from avian myeloblastosis virus (amv). | subgenomic fragments were released from purified 35s amv rna using strongly denaturing conditions of 78% formamide and 3.9 m urea at 53 degrees c. the fragments were characterized by sedimentation and electron microscopic analysis. the presence of five distinct, reproducible size classes of rna molecules with mean lengths 1.79 +/- 0.07 micron, 1.36 +/- 0.09 micron, 1.03 +/- 0.09 micron, 0.7 +/- 0.08 micron, and 0.42 +/- 0.09 micron were demonstrated. analysis of poly(a)+ and poly(a)- rna fragmen ... | 1983 | 6138994 |
| processive nature of reverse transcription by avian myeloblastosis virus deoxyribonucleic acid polymerase. | the ribonucleic acid dependent deoxyribonucleic acid polymerase from avian myeloblastosis virus was shown to synthesize poly(dt) transcripts by a processive mechanism using poly(ra)1100.oligo(dt)12-18 as template and primer. template challenge experiments demonstrate that at low temperature and ionic strength, the polymerase remains bound to the completed template-daughter strand complex after completion of daughter strand elongation. higher temperatures and ionic strength increase the dissociat ... | 1980 | 6153267 |
| enzymatic activities associated with avian and murine retroviral dna polymerases. catalysis of and active site involvement in pyrophosphate exchange and pyrophosphorolysis reactions. | reverse transcriptase isolated from avian myeloblastosis virus (amv) and rauscher murine leukemia virus (rlv) were examined for their ability to catalyze polymerization, ribonuclease h, pyrophosphate exchange, and pyrophosphorolysis reactions. a detailed characterization and a study of requirements for the expression of pyrophosphate exchange and pyrophosphorolysis reactions indicated that a variety of rna and dna template-primers supported these catalytic reactions. furthermore, hydrogen bondin ... | 1980 | 6153389 |
| structural requirements for binding of bovine trnatrp with avian myeloblastosis virus dna polymerase. | avian dna polymerases use host trnatrp as the primer for transcription. bovine trnatrp has been previously shown to be a biologic substitute for the avian primer. a bovine trnatrp fragment has been identified as having a high binding affinity for the polymerase. the fragment is assigned to be 67 nucleotides, and contains most of the elements required to maintain the secondary and tertiary structure of trnatrp. | 1980 | 6153465 |
| butylanilinouracil: a selective inhibitor of hela cell dna synthesis and hela cell dna polymerase alpha. | a series of 6-anilinouracils, dgtp analogues which selectively inhibit specific bacterial dna polymerases, were examined for their capacity to inhibit purified dna polymerases from hela cells. the p-n-butyl derivative (buau) was found to inhibit dna polymerase alpha with a ki of approximately 60 microm. the inhibitory effect of buau was reversed specifically by dgtp and was observed only for dna polymerase alpha; polymerases beta and lambda were not inhibited by drug at concentrations as high as ... | 1980 | 6153466 |
| a simple purification of avian myeloblastosis virus reverse transcriptase for full-length transcription of 35 s rna. | 1980 | 6153516 | |
| enzymatic synthesis of deoxyribonucleic acid by the avian retrovirus reverse transcriptase in vitro: optimum conditions required for transcription of large ribonucleic acid templates. | in this communication, we present data which describe optimum conditions for reverse transcription of large ribonucleic acid (rna) templates into deoxyribonucleic acid (dna) transcripts by the avian retrovirus reverse transcriptase in vitro. in contrast to previous studies, we have optimized all of the reaction components with respect to their influence on the size of dna transcripts rather than the incorporation of radio-labeled deoxynucleoside triphosphates into acid-insoluble dna product. the ... | 1980 | 6153530 |
| activation of an mg2+-dependent dna endonuclease of avian myeloblastosis virus alpha beta dna polymerase by in vitro proteolytic cleavage. | partial chymotryptic digestion of purified avian myeloblastosis virus alpha beta dna polymerase resulted in the activation of a mg2+-dependent dna endonuclease activity. incubation of the polymerase-protease mixture in the presence of super-coiled dna and mg2+ permitted detection of the cleaved polymerase fragment possessing dna nicking activity. protease digestion conditions were established permitting selective cleavage of beta to alpha, which contained dna polymerase and rnase h activity and ... | 1980 | 6154149 |
| radioimmunological comparison of the dna polymerases of avian retroviruses. | 125i-labeled dna polymerases of avian myeloblastosis virus and spleen necrosis virus were used in a radioimmunological characterization of avian retrovirus dna polymerases. it was shown that avian leukosis virus and reticuloendotheliosis virus dna polymerases do not cross-react in radioimmunoassays. within the avian leukosis virus species, species-specific and type-specific antigenic determinants of the dna polymerase were defined. the previous finding of genus-specific antigenic determinants in ... | 1980 | 6154153 |
| inhibition of virion-associated reverse transcription by nucleoside triphosphatase in avian myeloblastosis virus. | rna-dependent dna polymerase activity of avian myeloblastosis virions as measured by the incorporation of [3h]ttp into trichloroacetic acid-precipitable material was very low. this apparent low polymerase activity was observed with virions isolated either from leukemic chicken plasma or from the supernatant of cultured leukemic myeloblasts. the inhibition of reverse transcriptase activity was caused by nucleoside triphosphatase present in avian myeloblastosis virions and could be reversed by adp ... | 1980 | 6154806 |
| transcription maps of polyoma virus-specific rna: analysis by two-dimensional nuclease s1 gel mapping. | 1980 | 6154876 | |
| lactose operator--repressor interaction: use of synthetic oligonucleotides in determining the minimal recognition sequence of the lactose operator. | 1980 | 6154878 | |
| native ribonucleoprotein is an efficient transcriptional complex of avian myeloblastosis virus. | a native ribonucleoprotein (rnp) complex of avian myeloblastosis virus was prepared under conditions that gave optimal cdna synthesis. the complex was an autonomous transcriptional unit capable of synthesizing dna complementary to the rna virus genome in the absence of exogenous reverse transcriptase (rna-dependent dna nucleotidyltransferase), genomic rna, and primer. the rna of the rnp complex cannot be translated in an in vitro cell-free translational system. the rnp contains intact viral rna, ... | 1980 | 6154928 |
| rna primer used in synthesis of anticomplementary dna by reverse transcriptase of avian myeloblastosis virus. | when either the homologous rna (avian myeloblastosis virus rna) or a heterologous rna (poliovirus rna) was used as a template, the anticomplementary dna synthesized in vitro by avian myeloblastosis virus reverse transcriptase (rna-directed dna nucleotidyltransferase, ec 2.7.7.7) was primed by fragments of the original rna template that usually had adenosine at their 3' ends. when we used phage t/ rna ligase (ec 6.5.1.3) to label the 3' end of the rna template fragments contained in the rna . cdn ... | 1980 | 6154930 |
| mechanism of inhibition of the avian myeloblastosis virus deoxyribonucleic acid polymerase by adriamycin. | 1980 | 6155137 | |
| protein synthesis in cell-free extracts from pea primary axes [proceedings]. | 1980 | 6155836 | |
| synthesis of a full length dna complementary to thyroglobulin 33 s messenger rna. | 1980 | 6155911 | |
| properties of the reverse transcription of synthetic and hamster retroviral rna by avian and hamster viral polymerases. | 1980 | 6155913 | |
| reverse transcription of 25s soybean ribosomal rna in the absence of exogenous primer. | 1980 | 6155915 | |
| [study of influenza virus 4s rna as a primer in reverse transcription]. | the capacity of influenza virion 4s rna for serving as low-molecular primer has been studied in rna-directed dna synthesis catalyzed in vitro by reverse transcriptase of avian myeloblastosis virus. 4s rna purified by 8% polyacrylamide gel electrophoresis has been shown to stimulate the reverse transcription reaction in vitro and to be rna primer. the stimulating activity of the primers has been shown to decrease as follows: 4s nuclear rna of the rat liver oligo (dt)12-18 4s rna of influenza viri ... | 1980 | 6155954 |
| detection, sizing, and quantitation of polyadenylated ribonucleic acid in the nanogram-picogram range. | a method is described for using very high specific activity [3h]poly(deoxythymidylate) [[3h]poly(dt)] to detect, size, and quantiate subnanogram amounts of nonradioactive polyadenylated rna. short (approximately 100 nucleotides long) [3h]poly(dt) is hybridized to the poly(adenylate) [poly(a)] tracts in polyadenylated rnas. the rna may then be sized and quantitated by sucrose gradient analysis. the addition of the small [3h]poly(dt) molecules does not significantly alter the s values of rnas. the ... | 1980 | 6157400 |
| hybridization studies of poly a-rna from 5'-bromodeoxyuridine treated neuroblastoma cells. | hybridization studies were carried out to measure sequence complexity and relative complexity of poly a-rna populations from m1 neuroblastoma cells cultivated under proliferating conditions and after brdu treatment. brdu treatment is known to induce morphological differentiation. hybridization kinetics were performed with [3h] labelled complementary dna synthetized by reverse transcriptase action. the total complexities and the complexities of three classes of sequences measured for the two deve ... | 1980 | 6157427 |
| synthesis in high yield of complementary dna of retroviral rna. | mouse mammary tumor virus rna was transcribed in vitro with avian myeloblastosis virus reverse transcriptase in the presence of calf thymus dna oligomers. the yield of cdna was markedly enchanced by increasing the concentration of the enzyme as well as primers in the reaction mixture. the average size of cdna was approximately 200 residues, and it was not affected by the concentration of deoxynucleoside triphosphates when saturating concentration of enzyme was used. nearly all of the viral seque ... | 1980 | 6158040 |
| [enzymology of reverse transcription]. | 1980 | 6158678 | |
| sequence rearrangement and duplication of double stranded fibronectin cdna probably occurring during cdna synthesis by amv reverse transcriptase and escherichia coli dna polymerase i. | two cloned cdnas derived from the mrna for cell fibronectin have been sequenced, providing evidence that transcription with amv reverse transcriptase or escherichia coli dna polymerase i may not always result in double stranded cdna that is exactly homologous with its mrna template. instead, the sequences of these cloned cdnas are consistent with the duplication and rearrangement of sequences during synthesis of double stranded cdna. | 1980 | 6159581 |
| sequence complexity of cdna transcribed from a diverse mrna population. | mouse liver poly(a)+mrna was reverse transcribed using oligo-p(dt) or random oligonucleotides as primers to yield cdna about equal to the mass of the template rna. the size profile of the oligo-p(dt)-primedd cdna was similar to that of the template rna. rna or cdna driven saturation annealing of labeled single copy genomic dna (scdna) showed that 2% of the scdna was complementary in either case indicating the sequence complexity of cdna was equivalent to that of the template mrna. these results ... | 1980 | 6159588 |
| reactivity of reverse transcriptase toward (s4u,u)n copolymers and spin-labeled nucleic acid lattices. | spin-labeled copolymers of 4-thiouridine and uridine (ls4u,u)n] that contain various amounts of spin label (l) were synthesized by either (i) chemical alkylation of the 4-thiouridine-uridine copolymers (s4u,u)n prepared by copolymerizing 4-thiouridine 5'-diphosphate (s4udp) and udp or (ii) copolymerization of spin-labeled s4udp with udp using polynucleotide phosphorylase. the effect of (s4u,u)n and (ls4u,u)n on avian myeloblastosis virus (amv) rna-dependent dna polymerase (rna-dependent dna nucl ... | 1980 | 6159632 |
| genetic structure of avian myeloblastosis virus, released from transformed myeloblasts as a defective virus particle. | chicken myeloblasts transformed by avian myeloblastosis virus (amv) in the absence of nondefective helper virus (termed nonproducer cells) were found to release a defective virus particle (dvp) that contains avian tumor viral gag proteins but lacks envelope glycoprotein and a dna polymerase. nonproducer cells contain a pr76 gag precursor protein and also a protein that is indistinguishable from the pr180 gag-pol protein of nondefective viruses. the rna of the dvp is 7.5 kilobases (kb) long and i ... | 1980 | 6159639 |
| amino acid sequence analysis of reverse transcriptase subunits from avian myeloblastosis virus. | the nh(2)-terminal amino acid sequences of the alpha and beta chains of avian myeloblastosis alphabeta dna polymerase were determined by using microsequence analysis in the subnanomole range and were found to be identical up to 17 residues. the common sequence was as follows: thr-val-ala-leu-his-leu-ala-ile-pro-leu-lys-trp-lys-pro-asn-his-thr-. this result provides convincing chemical evidence that the alpha chain is derived from the nh(2)-terminal region of the beta chain by proteolytic cleavag ... | 1980 | 6160262 |
| study of the interactions between avian myeloblastosis virus reverse transcriptase and primer trna. affinity labeling and inactivation of the enzyme by periodate-treated trnatrp. | reverse transcriptase from avian myeloblastosis virus can react with periodate-treated primer trnatrp (beef) to form a schiff's base between an epsilon-nh2 lysine group within the active center of the enzyme and the dialdehyde derivative of the 3' terminal ribose of trna. in the presence of cyanoborohydride the reversible imminium moiety of the schiff's base is reduced to a more stable adduct. non-primer trnas were not able to reduce the extent of primer fixation to the enzyme. complete inactiva ... | 1980 | 6160474 |
| molecular cloning of pst i fragments from rat double stranded thyroglobulin complementary dna. | 1980 | 6160854 | |
| photochemical cross-linking studies on the interactions of avian myeloblastosis virus reverse transcriptase with primer trnatrp and ttp. | 1980 | 6162424 | |
| mechanism of action of moloney murine leukemia virus rna-directed dna polymerase associated rnase h (rnase h i). | the mechanism of action of the ribonuclease h (rnase h) activity associated with moloney murine leukemia virus rna-directed dna polymerase (rnase h i) and the two-subunit (alpha beta) form of avian myeloblastosis virus dna polymerase were compared by utilizing the model substrate (a)n.(dt)n and polyacrylamide gel electrophoresis in 7 m urea to analyze digestion products. examination on 25% polyacrylamide gels revealed that a larger proportion of the rnase h i oligonucleotide products generated b ... | 1981 | 6162482 |
| avian retrovirus rna-directed dna synthesis by purified reverse transcriptase. covalent linkage of rna to plus strand dna. | 1980 | 6163427 | |
| inhibition of avian myeloblastosis virus reverse transcriptase by ethidium bromide: effect on enzyme activity and primer trna recognition. | 1980 | 6163656 | |
| characterization of an inhibitor of granulocyte/monocyte colony formation in leukemic chicken plasma. | the plasma of chicks with myeloblastic leukemia (induced by avian myeloblastosis virus, amv) contained an inhibitor which blocked colony formation in vitro by marrow cells. it eluted in the second protein peak obtained by sephadex g-200 gel filtration and was found in the diafiltrate following defiltration through a um 10 membrane under acidic conditions. it was not extractable with chloroform, was heat-stable (65 degrees c, 30 min), pronase-sensitive and had a molecular weight less than or equa ... | 1981 | 6165604 |
| virus-coded dna endonuclease from avian retrovirus. | reverse transcriptase from avian retrovirus has a physically associated dna endonuclease with novel substrate and cofactor requirements. a similar endonuclease activity copurifies with pp32, a protein from viral cores that has been identified with the non-alpha region of the beta subunit of reverse transcriptase. several temperature-sensitive mutants of avian retrovirus with thermolabile dna polymerase were tested for thermal sensitivity of their dna endonuclease activity. two pol mutants of rou ... | 1981 | 6165835 |
| sites of termination of in vitro dna synthesis on ultraviolet- and n-acetylaminofluorene-treated phi x174 templates by prokaryotic and eukaryotic dna polymerases. | in vitro dna synthesis on a phi x174 template primed with a restriction fragment and catalyzed by the escherichia coli dna polymerase i large (klenow) fragment (pol i) terminates at the nucleotide preceding a site that has been altered by ultraviolet irradiation or treatment with n-acetylaminofluorene. termination on ultraviolet-irradiated templates is similar when synthesis is catalyzed by e. coli dna polymerase iii holoenzyme (pol iii), phage t4 dna polymerase, a polymerase alpha from human ly ... | 1981 | 6165985 |
| effect of heme on globin messenger rna synthesis in spleen erythroid cells. | synthesis of globin mrna in erythroid spleen cells from anemic mice was measured after in vitro incubation under conditions in which the level of intracellular heme was manipulated. this newly synthesized globin mrna was isolated by hybridization with globin cdna covalently bound to cellulose. isonicotinic acid hydrazide (inh) and penicillamine were used as specific inhibitors of heme synthesis. it has been found that a 120-min incubation of spleen erythroid cells with 5mm inh or 5mm penicillami ... | 1981 | 6166793 |
| 5'-terminal sequences of eucaryotic mrna can be cloned with high efficiency. | a method for cloning mrnas has been used which results in a high yield of recombinants containing complete 5'-terminal mrna sequences. it is not dependent on self-priming to generate double-stranded dna and therefore the s1 nuclease digestion step is not required. instead, the cdna is dcmp-tailed at its 3'-end with terminal deoxynucleotidyl transferase (tdt). the synthesis of the second strand is primed by oligo(dg) hybridized to the 3'-tail. double-stranded cdna is subsequently tailed with dctp ... | 1981 | 6166921 |
| effect of atp on the friend murine leukemia virus-associated endonuclease activity and the endonuclease activity of the avian myeloblastosis virus rna-directed dna polymerase. | the mn2+-dependent endonuclease activity associated with the avian myeloblastosis virus rna-directed dna polymerase has been shown to be activated by atp in the presence of mg2+. in the presence of mn2+ the endonucleolytic activity was stimulated about 3-fold by the addition of atp. the earlier identified mr = 40,000 friend murine leukemia virus (f-mulv)-associated endonuclease which functions in the presence of both mg2+ and mn2+ has also been shown to be similarly stimulated by atp. for both e ... | 1981 | 6167571 |
| purification of reverse transcriptase from avian retroviruses using affinity chromatography on heparin-sepharose. | reverse transcriptase from rous sarcoma virus and avian myeloblastosis virus was purified by a rapid two-step procedure using chromatography on phosphocellulose and heparin-sepharose. the resulting enzyme was homogeneous, had a high specific activity and was free of contaminating nucleases. this procedure has been adapted to small-scale preparation of enzyme from mutant virus containing thermolabile reverse transcriptase, and is equally suitable for large-scale enzyme purification. | 1980 | 6168644 |
| the artifactual nature of fluoride inhibition of reverse transcriptase and associated ribonuclease h. | 1981 | 6169342 | |
| template-binding site of amv reverse transcriptase and inactivation of the enzyme by n-ethylmaleimide. | n-ethylmaleimide, a sulfhydryl-specific reagent, strongly inhibits amv reverse transcriptase by specifically interfering with the template-binding site of the enzyme. however, the kinetics of inhibition differ widely with the composition and structure of the templates employed. the copying of templates with multiple 3'-hydroxyl termini appeared to be more susceptible to n-ethylmaleimide treatment, suggesting that the reagent may interfere with initiation of dna synthesis. the ability of a templa ... | 1981 | 6169371 |
| construction and identification of a hybrid plasmid containing dna sequence complementary to phenobarbital-inducible cytochrome p-450 messenger rna from rat liver. | cytochrome p-450 mrna has been partially purified from membrane-bound polysomes of the livers of phenobarbital-treated rats by sds-phenol-chloroform extraction, followed by poly(u)-sepharose chromatography and by centrifugation through a sucrose density gradient. cytochrome p-450 mrna activity was detected near 18s in the sucrose density gradient, accounting for approximately 5% of total mrna activity on the basis of [3h]leucine incorporation in an in vitro translation system of wheat germ. comp ... | 1981 | 6169709 |
| antiviral properties of polyinosinic acids containing thio and methyl substitutions. | polyinosinic acids containing methyl and sulphur substitutions are potent inhibitors of reverse transcriptase. substitution of sulphur for oxygen at the 6 position produces significant effects on the properties of polyinosinic acid: the kinetics of inhibition change from competitive to mixed-type and the inhibition constant falls by three orders of magnitude. in contrast, 1-methyl substitution produces no such effects. poly(1-methyl-6-thioinosinic acid) or poly(m1s6i) inhibits irreversibly, inhi ... | 1981 | 6169784 |
| properties of the avian viral protein p12. | the avian rna tumour virus structural protein p12 was purified from avian myeloblastosis virus (amv) by nucleic acid affinity chromatography to apparent homogeneity as judged from sds--polyacrylamide gel electrophoresis. a filter binding assay was used for the identification of p12. high concentrations of p12 precipitated nucleic acids out of solution in the absence of mgcl2. binding of p12 to single-stranded nucleic acids protected them from digestion with nucleases and resulted in a hyperchrom ... | 1981 | 6169796 |
| molecular cloning of complementary dna to swine pepsinogen mrna. | poly(a)-containing rna was isolated from total rna of swine gastric mucosa by oligo(dt)-cellulose chromatography, and was translated in a wheat germ cell-free system. analysis of the translation products by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that pepsinogen was a major translation product and was synthesized as two different molecular forms with apparent molecular weights of 45,000 and 43,000. the pepsinogen translated in the in vitro translation system had no aut ... | 1981 | 6170644 |
| [enzymatic synthesis and molecular cloning of the pigeon alpha-globin structural gene]. | double-stranded dna synthesized from the pigeon globin mrna by the subsequent actions of avian myeloblastosis virus reverse transcriptase and e. coli dna polymerase i was split with nuclease s1 and inserted into psti site in the plasmid pbr322 by poly(dg) times poly(dc) homopolymer extension technique using terminal deoxynucleotidyl transferase. e. coli transformants have been shown to contain pigeon globin sequences by colony hybridization with pigeon globin [32p]cdna. the inserted dna fragment ... | 1981 | 6172703 |
| inhibition of reverse transcriptase by tyrosinase generated quinones related to levodopa and dopamine. | several derivatives of levodopa have been shown to be potent inhibitors of the sulfhydryl enzyme, rna dependent dna polymerase, reverse transcriptase (rt). in the presence of the polyphenol oxidase, tyrosinase, the inhibitory values were between 10(-6) m and 10(-5) m. structure-activity studies revealed that active oxidation or reduction was necessary for this potent inhibitory response. spectrophotometric analysis showed that the presence of both the quinone and quinol was required for maximum ... | 1981 | 6173137 |
| preparation of cdna, ds cdna, and tailed ds cdna from interferon mrna templates. | 1981 | 6173719 | |
| inability of avian myeloblastosis virus rna-directed dna polymerase to transcribe poly(ru) due to instability of the oligo(da): poly(ru) complex. | 1981 | 6174121 | |
| the synthesis of dna complementary to polyadenylate-containing rna from bacillus subtilis. | we had shown earlier (gopalakrishna, y., langley, d., sarkar, n. (1981) nucleic acid res. 9, 3545-3554) that a substantial fraction of mrna of various bacterial species carries 3'-terminal polyadenylate sequences. in this paper, we show that poly(a)-containing rna from bacillus subtilis can serve as template for the synthesis of complementary dna by avian myeloblastosis virus reverse transcriptase, provided that oligodeoxythymidylate is added as primer. poly(a)-rna purified by affinity chromatog ... | 1982 | 6174511 |
| reverse transcription of avian myeloblastosis virus 35s rna. early synthesis of plus strand dna of discrete size in reconstructed reactions. | the early dna products of reverse transcription have been analyzed from reconstructed reactions containing avian myeloblastosis virus 35s rna . trnatrp complex and highly purified reverse transcriptase. we describe conditions for the synthesis of genome-length complementary dna and two discrete species of plus strand dna (the same chemical polarity as the viral rna genome) about 300 and 400 nucleotides in length. plus dna400 and plus dna300 were detected by molecular hybridization with dna probe ... | 1982 | 6174940 |
| reverse transcriptase associated with avian sarcoma-leukosis viruses. i. comparison of intra-virion content of multiple enzyme forms. | the rna-dependent dna polymerase (the reverse transcriptase) was solubilized from three related strains of avian sarcoma virus (asv b77, asv tsla334, and asv qv2) as well as avian myeloblastosis virus (amv) and a chicken endogenous virus (rav-o), by a combination of non-ionic detergent treatment and cscl step-gradient centrifugation, and was subsequently separated into individual enzyme forms by poly(c)-agarose column chromatography. the newly developed two-step method allowed us to purify the t ... | 1982 | 6175623 |
| reverse transcriptase associated with avian sarcoma-leukosis viruses. ii. comparison of subunit structure and catalytic properties. | the three enzyme forms (alpha, alpha beta-, and beta-form) of the rna-dependent dna polymerase (the reverse transcriptase) from three strains of avian sarcoma virus (asv b77, asv tsla334, and asv qv2) and one exogenous (avian myeloblastosis virus (amv)) and one endogenous avian leukosis virus (rous-associated virus type-0 (rav-0) were compared with each other in subunit structure and catalytic properties. despite the gross similarity in the subunit molecular weight (mr(alpha) = 65,000 and mr(bet ... | 1982 | 6175624 |
| binding of nucleotide spin probes to amv reverse transcriptase and metal ions. | 1982 | 6176469 | |
| restriction map of poliovirus type 2 cdna. | poliovirus type 1 rna was reverse-transcribed into c-dna and inserted at the pst i site of the plasmid vector pbr322 of e. coli. resulting recombinant plasmids were analyzed by hybridization with rnase t1-resistant 32p-labeled oligonucleotides, and by restriction enzyme mapping. all of the genome was cloned in a series overlapping cdna inserts, the longest of which was 3.2 kb. the restriction map of the poliovirus cdna is presented. | 1981 | 6176488 |
| differential inhibition of dna polymerase and rnase h activities of the reverse transcriptase by phosphonoformate. | three potential inhibitors of reverse transcriptase activities, phosphonoformate (pf), phosphonoacetate (paa), and ethyl-diethyl phosphonoformate (et-pf), were compared in this study. only pf was found to inhibit the dna polymerase activity of the purified reverse transcriptase of moloney murine leukemia virus (m-mulv) and avian myeloblastosis virus (amv). the degree of dna polymerase inhibition was linear with pf concentration; 50% inhibition was achieved at 10 mum. whereas pf inhibited both th ... | 1982 | 6178013 |
| stereochemical course of polymerization catalyzed by avian myeloblastosis virus reverse transcriptase. | the sp diastereomer of thymidine 5'-o-(1-thiotriphosphate) was polymerized by avian myeloblastosis virus reverse transcriptase using poly(a) . d(pt)10 as template-primer. degradation of the template poly(a) by alkaline hydrolysis and isolation by gel chromatography gave a single-stranded poly(d(p(s)t)), a polymer of thymidine 5'-phosphorothioate. to determine the configuration of the phosphorothioate internucleotide linkage, this material was degraded by snake venom phosphodiesterase. comparison ... | 1982 | 6178737 |
| 5-mercaptopolyuridylic acid (mpu), a potent inhibitor of the reverse transcriptase from avian myeloblastosis virus. | the effects of partially thiolated polyuridylic acid (mpu), partially thiolated polycytidylic acid (mpc), and their unmodified counterparts, poly(u) and poly(c), respectively, on the reverse transcriptase of avian myeloblastosis is virus (amv) have been determined, using different template-primers. poly(c) stimulated and mpc inhibited the polymerization reaction catalyzed by the amv reverse transcriptase in the presence of the natural viral template (endogenous rna or purified 70s rna), or with ... | 1982 | 6179137 |
| inhibition of reverse transcriptase activity of avian myeloblastosis virus by pyrophosphate analogues. | several pyrophosphate analogues have been studied for their effects on avian myeloblastosis virus reverse transcriptase and on cellular dna polymerase alpha. examination of structure-activity relationships for these compounds revealed that two acidic groups connected by a short bridge were necessary, but not sufficient, for inhibition of the enzyme activities. foscarnet sodium (trisodium phosphonoformate) was the most potent inhibitor of reverse transcriptase, giving non-competitive inhibition o ... | 1982 | 6179470 |
| mechanism of linear dna circularization: formation of 'lasso'-like structures of pre-mrna dna copies. | an electron microscopic investigation of a dna product synthesized on the pre-mrna template using amv reverse transcriptase in the absence of actinomycin d revealed linear single-stranded and double-stranded molecules, and, also, double-stranded branched as well as 'lasso'-like and circular structures. models for the formation of such dna structures are proposed. | 1982 | 6181388 |
| rose bengal mediated inhibition of dna polymerases: mechanism of inhibition of avian myeloblastosis virus reverse transcriptase under nonoxidative conditions. | 1982 | 6182904 | |
| interactions between dna polymerase and aminofluorene adducts that affect the recognition and possibly the mutagenicity of the lesions. | adducts of 2-aminofluorene on the c-8 position of guanine block dna synthesis and lead to mutation. n-acetylated adducts adopt the syn conformation such that in dna the guanine is displaced from the helix by the fluorene ring while unacetylated adducts prefer the anti conformation allowing normal base pairing of the guanine with cytosine. in vitro synthesis by both e. coli dna polymerase i and t4 dna polymerase terminates predominantly one nucleotide before acetylated adducts but has an increase ... | 1982 | 6182925 |
| antibodies to reverse transcriptase of avian oncoviruses in sera of specific-pathogen-free chickens. | 1982 | 6183954 | |
| lymphoid leukosis: detection of group specific viral antigen in chicken spleens by immunofluorescence and complement fixation. | monospecific antiserum obtained from rabbits hyperimmunized against homogeneous p27 group specific protein purified from avian myeloblastosis virus was commercially procured and was then conjugated with fluorescein isothiocyanate. the conjugate was applied to spleens from naturally or experimentally infected chickens that had no evidence of lymphoid tumors. fluorescence was usually localized in connective tissue of sheathed capillaries giving it a ring-like appearance. sites of fluorescence corr ... | 1982 | 6184143 |
| inhibition of avian myeloblastosis virus reverse transcriptase and virus inactivation by metal complexes of isonicotinic acid hydrazide. | the cupric and ferric complexes of isonicotinic acid hydrazide (inh) inhibit the dna synthesis catalysed by avian myeloblastosis virus (amv) reverse transcriptase. the inhibition was to the extent of 95% by 50 microm of cupric-inh complex and 55% by 100 microm of ferric-inh complex. these complexes have been found to bind preferentially to the enzyme than to the template-primer. kinetic analysis showed that the cupric-inh complex is a non-competitive inhibitor with respect to dttp. the time cour ... | 1982 | 6185090 |
| avian myeloblastosis reverse transcriptase deacylates tryptophanyl-trna. | tryptophanyl-trna can be used as a primer for rna-dependent dna synthesis by avian reverse transcriptase. we have determined that whereas the retroviral polymerase is not by itself capable of deacylating trp-trnatrp, the ester linkage between the 3' oh of the ribose moiety and the aminoacid can be very efficiently hydrolyzed when both the polymerase and the viral 35 s rna are present. | 1982 | 6185923 |
| effect of acetylated and deacetylated 2-aminofluorene adducts on in vitro dna synthesis. | we have constructed primed phi x174 dna templates containing either acetylated or deacetylated aminofluorene adducts at the c-8 position of guanine. t4 dna polymerase terminates synthesis one nucleotide before the acetylated adducts but incorporates an additional nucleotide opposite the deacetylated guanylaminofluorene. these observations can be explained by the known preferred conformations of the acetylated and deacetylated guanosinylaminofluorene nucleosides--the former favoring the syn confo ... | 1982 | 6185946 |
| tandemly repeated hexanucleotide at tetrahymena rdna free end is generated from a single copy during development. | the linear extrachromosomal ribosomal dna of tetrahymena is generated from a single integrated copy during macronuclear development. the free ends of this extrachromosomal gene contain 20-70 tandem repeats of the hexanucleotide ccccaa. we have determined the nucleotide sequence at the same (3') end of the single, integrated micronuclear gene. in contrast to the extrachromosomal gene, only a single ccccaa sequence was found at this position. the same result was obtained from two independently iso ... | 1982 | 6186380 |
| interaction of polymerases with 2'-deoxyuridine-5'-triphosphate spin-labeled at the 5-position. | 2'-deoxyuridine-5'-triphosphate spin-labeled at the 5-position with n-[1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl]-o- was found to be an inhibitor of some dna and rna polymerases including avian myeloblastosis virus reverse transcriptase. furthermore, the spin-labeled nucleotide was found to be incorporated internally into polydeoxythymidylic acid via reverse transcriptase to an extent of 1.0 spin-labeled base per 10(3) bases. the incorporation, monitored by electron spin resonance, is analogous t ... | 1983 | 6186529 |
| synthesis of full-length cdnas from partially purified human procollagen mrnas. | partially purified human procollagen mrnas have been copied using reverse transcriptase from avian myeloblastosis virus. under standard conditions, using a high deoxynucleotide concentration, only incomplete cdnas corresponding to one-fifth to one-half of the template could be synthesized. addition of a ribonuclease inhibitor from human placenta in the reaction mixture allowed the synthesis of full-length cdna copies from extremely long procollagen mrna. | 1982 | 6186901 |
| reverse transcription of yeast double-stranded rna and ribosomal rna using synthetic oligonucleotide primers. | the ability of the four oligodeoxyribonucleotide primers oligo(dt)12-18, oligo(da)12-18, oligo(dg)12-18 and oligo(dc)12-18 to act as primers for avian myeloblastosis virus reverse transcriptase on denatured yeast double-stranded (ds) rna templates was investigated. oligo(dt) and oligo(da) were found to prime the synthesis of 1.1 and 1.0 kb reverse transcripts, respectively, using denatured m dsrna as a template. the oligo(dt)- and oligo(da)-primed cdnas of m dsrna hybridized to the region of the ... | 1983 | 6187364 |
| mechanism of action of the endonuclease associated with the alpha beta and beta beta forms of avian rna tumor virus reverse transcriptase. | preparations of the alphabeta and the betabeta forms of reverse transcriptase from the prague c strain of rous sarcoma virus grown in chicken embryo fibroblasts, the alphabeta and the betabeta forms of the enzyme from the b77 strain of rous sarcoma virus grown in duck embryo fibroblasts, and the alphabeta form of reverse transcriptase from avian myeloblastosis virus have been analyzed. all these enzyme preparations contain a mn(2+) -activated endonuclease activity. the betabeta form of enzyme, i ... | 1983 | 6187936 |
| production and characterization of monoclonal antibodies against avian retrovirus reverse transcriptase. | monoclonal antibodies were prepared against the avian myeloblastosis virus reverse transcriptase. these monoclonal antibodies specifically immunoprecipitated the alpha and beta subunits of the reverse transcriptase molecule, as well as the pr180gag-pol precursor protein present in virus-infected cells. in addition, these monoclonal antibodies inhibited the dna polymerase activity associated with the reverse transcriptase molecule but not the rnase h activity. the monoclonal antibody preparations ... | 1983 | 6187937 |
| involvement of trna in retrovirus expression: biological implications of reverse transcriptase-primer trna interactions. | we have previously studied the topographical and functional implications of the recognition of primer trnatrp by avian retrovirus reverse transcriptase. here we have presented evidence that the enzyme is able to deacylate beef liver trp-trnatrp, provided that 35-s viral rna is present in the incubation mixture. no effect of dntps on this activity was observed. the extensive modification of trnatrp with acrylonitrile led to a marked loss of priming activity by trnatrp if the annealing between pri ... | 1983 | 6189158 |
| inhibition of reverse transcriptases by seminalplasmin. | seminalplasmin, an antibacterial protein present in bovine seminal plasma, is shown to be a potent inhibitor of reverse transcriptases (rna-dependent dna nucleotidyltransferases). seminalplasmin inhibits rna-directed, hybrid-directed, and dna-directed dna-polymerizing activities of purified reverse transcriptase from avian myeloblastosis virus and from crude viral lysates of several retroviruses by binding to the enzyme, at least in the case of avian myeloblastosis virus. seminalplasmin does not ... | 1983 | 6189479 |
| interaction of new anthracycline antibiotics with dna. effects on nucleic acid synthesis and binding to dna. | the effects of various new anthracycline antibiotics on dna and rna synthesis were studied using dna polymerase i (ec 2.7.7.7), rna polymerase (ec 2.7.7.6) obtained from escherichia coli and reverse transcriptase obtained from avian myeloblastosis virus. aclacinomycin a, its analogues, baumycins a1 and a2, adriamycin and daunomycin showed potent inhibitory effects on these polymerases, with calf thymus dna as template, with ic50 values of 10-30 microm. with poly(ra) x d(pt)10 as template for rev ... | 1983 | 6189517 |
| the mechanism of inhibition of avian myeloblastosis virus reverse transcriptase by a dialdehyde derivative of atp. inactivation of essential sulfhydryl group function. | the dialdehyde derivative of atp inhibits dna synthesis by amv reverse transcriptase, while the polymerase-associated ribonuclease h activity is significantly resistant to this reagent. neither atp nor its dialcohol form effectively block dna synthesis, indicating that the aldehyde moiety is required for inhibition. the nature of the reactivity of dialdehyde-atp with amv reverse transcriptase has been examined and we find that: (a) inhibition is non-competitive with respect to substrate deoxynuc ... | 1983 | 6189518 |
| rose bengal mediated inhibition of dna polymerases: mechanism of inhibition of avian myeloblastosis virus reverse transcriptase under photooxidative conditions. | dna polymerases from prokaryotic, eukaryotic, and oncornaviral sources are irreversibly inactivated upon exposure to rose bengal in the presence of light (photooxidation conditions). inactivation of these enzymes under dark (nonoxidative) conditions is totally reversible [srivastava, s. k., & modak, m. j. (1982) biochemistry 21, 4633-4639]. the primary effect of photooxidation on the enzyme-rose bengal complex was found to be the loss of template-primer binding ability within 5 min of exposure t ... | 1983 | 6190509 |
| enzyme inhibition vi: inhibition of reverse transcriptase activity by protoberberine alkaloids and structure-activity relationships. | protoberberine alkaloids such as palmatine (i), 13-methylpalmatine iodide (ii), 2,3-methylenedioxy-10,11-dimethoxy-13-methylprotoberberine iodide (iii), 2,3-methylenedioxy-9,10-dimethoxy-13-methylprotoberberine chloride (iv), and berberine (v) showed inhibition of reverse transcriptase activity of rna tumor viruses in the presence of polyriboadenylic acid-oligodeoxythymidylic acid (vi), polydeoxyadenylic acid-oligodeoxythymidylic acid (vii), activated calf thymus deoxyribonucleic acid (ix), and ... | 1983 | 6191021 |
| template specificities of a rna-directed dna polymerase from a human homologous mixed mesodermal sarcoma. | a rna-directed dna polymerase was partially purified from a human homologous, mixed mesodermal sarcoma by deae-cellulose chromatography after sucrose density centrifugation. the enzyme transcribed poly(ra) most effectively but also transcribed poly(ri), poly(da) and poly(rg) and to a lesser extent, poly(rmc). it was unable to transcribe poly(ru). the product with poly(ra) as template contained large material (greater than 28s) in addition to some proper size product demonstrating a slippage reac ... | 1983 | 6191264 |
| structural features required for the binding of trnatrp to avian myeloblastosis virus reverse transcriptase. | the basis of the specific binding of trnatrp by avian myeloblastosis virus reverse transcriptase was studied by chemical and enzymatic modification of the rna. binding does not depend on recognition of the tryptophan anticodon since molecules cleaved in the anticodon are stably bound by the enzyme. modification of pseudouridine residues in the trna destroys binding to reverse transcriptase. these results are consistent with a model in which reverse transcriptase-trnatrp interaction occurs not at ... | 1983 | 6192393 |
| a higher affinity of amv reverse transcriptase for template-primers correlates with a lower rate of dna synthesis. | the kinetics of copying of poly (a)--oligo (dt) and poly (c)--oligo (dg) by reverse transcriptase from avian myeloblastosis virus have been studied, and binding affinity of enzyme for template-primer and primer alone have been determined separately. although the maximal rate of dna synthesis obtained with poly (c)-oligo (dg) is higher than that for poly (a)-oligo (dt), the binding affinity of the enzyme for poly (c)-oligo (dg) or oligo (dg) is considerably lower than that for poly (a)--oligo (dt ... | 1983 | 6193009 |
| retrostatin, a new specific enzyme inhibitor against avian myeloblastosis virus reverse transcriptase. | a novel enzyme inhibitor against rna-directed dna polymerase of avian myeloblastosis virus was produced by an isolate of a new streptomycete for which the name streptomyces retrostaticus is proposed. this enzyme inhibitor, which was named retrostatin, did not inhibit dna-directed dna polymerase of escherichia coli and dna-directed rna polymerase of ehrlich ascites tumor cells. retrostatin was produced by the microorganism together with streptonigrin. these two substances were extracted from the ... | 1983 | 6193091 |
| [polyadenylation of influenza virion rna in an in vitro system]. | a method for isolation of terminal polyriboadenylate transferase from e. coli cells (mpe 600) is presented. the specific activity of the enzyme yield at the terminal stage was 933 units per 1 mg of protein. analysis of polyadenylated in vitro virion rna of influenza virus a/ussr/90/17 strain in polyacrylamideagarose gel (2.2%-0.6%) in the presence of 6 m urea showed all the 8 fragments of genome rna to be adenylated, their sizes being retained with regard to the distribution in gel of the initia ... | 1983 | 6193643 |
| synthesis of ds-cdna involving addition of dcmp tails to allow cloning of 5'-terminal m rna sequences. | 1983 | 6194405 | |
| the human dna locus related to the oncogene myb of avian myeloblastosis virus (amv): molecular cloning and structural characterization. | chicken and human cell dna contains sequences homologous to the avian myeloblastosis virus oncogene, v-myb. these cellular sequences, c-myb (human) and c-myb (chicken), were isolated from libraries of human or chicken cell dna fragments, generated by partial digestion with the restriction enzymes alui and haeiii, and compared. the chicken c-myb locus isolated from two distinct overlapping recombinant phages, contained five contiguous ecori fragments of 5.4, 1.1, 2.1, 2.2 and 9 kbp, accounting fo ... | 1983 | 6194989 |
| transduction of c-myb into avian myeloblastosis virus: locating points of recombination within the cellular gene. | the oncogene (v-myb) of avian myeloblastosis virus apparently arose by transduction of nucleotide sequences from a cellular gene (c-myb). in c-myb the nucleotide sequences that formed v-myb exist at seven distinct regions separated by nontransduced stretches of sequence that are flanked by eucaryotic splice signals. by contrast, the sequences at the outside boundaries of the transduced region of c-myb do not resemble splice sites. we mapped the nucleotide sequences that are homologous to the end ... | 1983 | 6195355 |
| use of monoclonal antibodies against avian retroviral protein p19 for competitive radioimmunoassay and immunodiffusion. | monoclonal antibodies were used in competitive binding assays to investigate the arrangement of three epitopes on the protein p19 of avian myeloblastosis virus (amv). it was reasoned that if the epitopes recognized by two monoclonal antibodies are physically close, the binding of one antibody will sterically block the binding of the second; conversely no blocking will occur if the epitopes are sufficiently distant. the results of these competitive binding assays demonstrated the presence of two ... | 1983 | 6197663 |
| early decline in c-myb oncogene expression in the differentiation of human myeloblastic leukemia (ml-1) cells induced with 12-o-tetradecanoylphorbol-13-acetate. | the relationship of oncogene expression to proliferation and differentiation has been examined in a line of human myeloblastic leukemia (ml-1) cells. proliferating leukemic cells were found to express a 4.3-kilobase cellular homologue (c-myb) of the transforming sequence of avian myeloblastosis virus. a rapid decline in the expression of this transcript was seen in cells induced to differentiate with 12-o-tetradecanoylphorbol-13-acetate. the level of c-myb rna was decreased by greater than 50% a ... | 1984 | 6198073 |
| affinity of reverse transcriptase for some polynucleotide inhibitors. | the relative affinity of avian myeloblastosis virus reverse transcriptase for (u)n and a series of (u)n analogs has been measured directly in solution under conditions previously used to demonstrate the inhibitory properties of these polynucleotides. the affinities were measured by electron spin resonance through a quantitative competition approach where the concentration of each polynucleotide required to compete with the macromolecular spin probe (ls4u,u)n for reverse transcriptase was observe ... | 1984 | 6198961 |
| mechanism of rna primer removal by the rnase h activity of avian myeloblastosis virus reverse transcriptase. | the single-stranded dna containing the moloney murine leukemia virus origin for plus-strand synthesis was cloned in m13mp2 and used as a template for avian myeloblastosis virus reverse transcriptase in the presence of moloney rna which had been treated with pancreatic rnase a. the rna pieces containing the polypurine stretch near the plus-strand origin were processed, presumably by rnase h, to generate primers for dna synthesis which initiated both at the correct origin site and at one nucleotid ... | 1984 | 6199510 |