Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly(A)-containing RNAs were isolated from morphologically different cells of the fungus Schizophyllum commune. Using mRNA markers the number-average length of poly(A)-containing RNA in total RNA and in purified poly(A)-containing RNA was estimated as 1100 nucleotides. Number-average length of poly(A)-tracts was 33 nucleotides. 2.5% of total RNA is poly(A)-containing RNA and probably up to 7.5% are non-polyadenylated polydisperse RNA sequences. Saturation hybridization of poly(A)-containing RNA to gap-translated [3H]DNA resulted in 16% of the reactive single-copy DNA to become S1 nuclease resistant. It was found that purified poly(A)-containing RNA represented the entire RNA complexity, i.e. 10 000 different RNA sequences in S. commune. RNA sequences isolated from morphologically different mycelia and from fruiting and non-fruiting mycelia were identical for at least 90%.
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PMID:Comparison of poly(A)-containing RNAs in different cell types of the lower eukaryote Schizophyllum commune. 57 52

The presence of viral-like sequences in the RNA of various types of leukemic cells was investigated by hybridizing cellular poly(A)-containing RNA with cDNA synthesized in an endogenous system of purified Moloney murine sarcoma virus [M-MSV-(MLV)]. Poly(A)-RNA-cDNA hybrids were detected by assaying their resistance to S1 nuclease. Hybrids were found in 22 out of the 46 leukemias that were tested. None of the controls, including material obtained from buffy coats, bone marrow cells, and a continuous human cell line, was positive. Positive cases were found in all the different categories of leukemias with the exception of chronic myelogenous leukemias. There was no definite corelation between the category of leukemia and positivity. A few cases contained a very high proportion of poly(A)-RNA-cDNA hybrid.
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PMID:Search for nucleic acid sequences complementary to a murine oncornaviral genome in poly(A)-rich RNA of human leukemic cells. 106 Oct 78

In our previous study, we identified four chromatographically distinct DNA-dependent ATPases, B, C1, C2, and C3, in mouse FM3A cells (Tawaragi, Y., Enomoto, T., Watanabe, Y., Hanaoka, F., and Yamada, M. (1984) Biochemistry 23, 529-533). The DNA-dependent ATPase C1 has been purified and characterized in detail. A divalent cation and a polynucleotide cofactor were required for the ATPase activity. Poly(dT), single-stranded circular DNA, and heat-denatured DNA were very effective. Almost no ATPase activity was observed with S1 nuclease-treated native DNA. ATPase C1 hydrolyzed ATP only among the ribo- and deoxyribonucleoside triphosphates tested, and this fact distinguished ATPase C1 from ATPases B, C2, and C3, because the latter enzymes are capable of hydrolyzing both ATP and dATP. The purified DNA-dependent ATPase C1 fraction was shown to have a DNA helicase activity that was dependent on hydrolysis of ATP. The helicase activity and DNA-dependent ATPase activity cosedimented at 5.2 S on glycerol gradient centrifugation. Both activities showed similar preferences for nucleoside 5'-triphosphates and similar requirements for divalent cations. The DNA helicase activity was inhibited by the addition of single-stranded DNAs that served as cofactor for the ATPase activity. The efficiency of a single-stranded DNA to inhibit DNA helicase activity correlated well with the capacity of the DNA to serve as cofactor for DNA-dependent ATPase activity. The helicase was shown to migrate along the DNA strand in the 5' to 3' direction, which is the same direction of migration of the mouse DNA helicase B (Seki, M., Enomoto, T., Yanagisawa, J., Hanaoka, F., and Ui, M. (1988) Biochemistry 27, 1766-1771).
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PMID:DNA-dependent adenosinetriphosphatase C1 from mouse FM3A cells has DNA helicase activity. 131 Sep 78

Trypanosomatid protozoan parasites utilize a number of nonstandard mechanisms in expressing their genes. To probe these phenomena in a genetically accessible system, we have mapped termini of eight transcripts arising from the amplified R region including the DHFR-TS gene of methotrexate-resistant Leishmania major. Poly(A)+ RNAs transcribed from the DHFR-TS-coding strand exhibit features similar to those observed around other trypanosomatid protein-coding genes. These include close spacing, the presence of a transpliced miniexon on the 5' termini, heterogeneity at both 5' and 3' ends, and in some cases S1 nuclease protection of intertranscript regions. Other than the splice acceptor site, no consensus sequence elements associated with either 5' or 3' ends were detected, although polydinucleotide tracts tended to be near inter-transcript regions. Two poly(A)+ RNAs transcribed from the opposite strand of the upstream flanking regions lacked the miniexon. Sequencing of DNA encoding the overlapping 1.7 kb opposite strand transcripts (one bearing and one lacking the miniexon, both found on polysomes) revealed no reading frames likely to encode proteins, suggesting that at least some of these RNAs could be nonfunctional by-products of RNA processing.
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PMID:Nuclease mapping and DNA sequence analysis of transcripts from the dihydrofolate reductase-thymidylate synthase (R) region of Leishmania major. 224 82

The behaviour of different batches of synthetic Poly(A).Poly(U) in reversed-phase high-performance liquid chromatography (HPLC) was studied. They consist of large molecules mainly in the form of a double strand. Differences in the elution patterns were correlated with properties detected by conventional methods such as electrophoresis, centrifugation, fusion analysis or enzymatic digestions. Under the present conditions, contamination by products and precursors used during synthesis was detectable, but was absent in most of the preparations. The differences in elution patterns between batches appear to be correlated with the size of the molecules synthesized. The chromatograms suggested that Poly(A).Poly(U) molecules contain single-strand portions at least transiently. The presence of such portions was confirmed by enzymatic digestion with S1 nuclease. The rapidity, reproducibility and ease of reversed-phase HPLC qualify this technique as a tool for routine analysis.
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PMID:Analysis of double-stranded poly(A).poly(U) molecules by reversed-phase high-performance liquid chromatography. 323 96

The interaction of poly-N6-methyladenylic acid (poly(m6A) with poly-5-bromouridylic acid (poly(BU) was studied by the mixing curve method. A.1 m6A: 2 BU stoichiometry was clearly indicated over a wide range of ionic strengths at neutral pH, while the binding of poly(m6A) to poly(U) is known to occur with 1 m6A:1 U. Digestion by nuclease S1 confirmed this stoichiometry, indicating the absence of single strands in a 1:2 mixture. Heating profile analysis and hydroxyapatite column chromatography provided further confirmation of this finding. To determine whether 1:2 stoichiometry holds in a monomer-polymer system, the interaction of N6-methyl-9-methyladenine (m6m9A), a corresponding monomer of poly(m6A), with poly(BU) was investigated. Equilibrium dialysis experiments showed the stoichiometry of the interaction to be 1 m6A:2 BU. Thus, we would describe some structural studies of the above complexes using c.d. and i.r. spectroscopy. Poly (m6A).2poly(BU) and m6m9A.2poly(BU) are helical and analogous to each other in structure, and the bases in the complexes are all bound by hydrogen-bonding. N6-(delta 2-isopentenyl)- and N6-allyl-9-methyladenine were also found to form complexes with poly(BU), giving similar c.d. spectra with that of m6m9A.2poly(BU). The melting experiments indicated the Tms to be substantially decreased, compared to the parent unmodified complexes, even though the Tm dependence of the polymer complex on salt concentration conforms to the typical triple strand. In the following, the biological significance of this novel pairing will be discussed.
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PMID:Interactions of poly-N6-methyladenylic acid and N6-substituted-9-methyladenines with poly-5-bromouridylic acid: a novel base-pairing. 391 14

Poly(dG-dC).poly(dG-dC) has been modified by reaction with 4-acetoxyaminoquinoline 1-oxide (Ac-4 HAQO), the ultimate carcinogen of 4-nitroquinoline 1-oxide. The circular dichroism (CD) spectra of the modified and unmodified polymers have been compared under various experimental conditions. The CD spectra were recorded in 1 mM phosphate, 50% (v/v) ethanol, 3.8 M LiCl and 95% (v/v) ethanol, conditions in which poly(dG-dC).poly(dG-dC) adopts the B-, Z-, C- and A-form respectively. In 1 mM phosphate buffer, poly(dG-dC).poly(dG-dC) modified by Ac-4 HAQO seems not to contain regions in the Z-form. Z-form induction could be progressively obtained by the addition of ethanol as follows: in the buffer with about 30% ethanol the modified polymer started to adopt the Z structure, while 40% of ethanol in the buffer was necessary for the unmodified polymer. In the 50% ethanol-1 mM phosphate buffer mixture (v/v), poly(dG-dC).poly(dG-dC) was entirely in the Z-form while poly(dG-dC).poly(dG-dC) modified by Ac-4 HAQO remained partially in the B-form. Enzymatic digestions with the nuclease S1 which is specific of the single-stranded DNA were carried out in order to support the modified poly(dG-dC).poly(dG-dC) CD study conclusions. The role played by the two major adducts on the conformational characteristics of modified polymer is discussed.
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PMID:Conformations of poly(dG-dC).poly(dG-dC) modified by the O-acetyl derivative of the carcinogen 4-hydroxyaminoquinoline 1-oxide. 609 58

Poly(A+)--RNA from rat ventral prostate was isolated using oligo(dT)-cellulose chromatography. 45% of the total poly(A+)--RNA was a single peak at 10S as demonstrated by centrifugation in a 5-20% sucrose gradient containing 1% SDS. By using complementary DNA probes, it was shown that the 10S RNA contained the major abundance class of poly(A+)--RNA. Denaturing agarose-gel analysis revealed 2 major bands in the 10S poly(A+)--RNA preparation approx. 600 NT and 500 NT (NT = nucleotides) long, resp. Double-stranded 32 P-DNAs complementary to light side and heavy side of the 10S poly(A+)--RNA peak were synthesized and isolated using reverse transcriptase and hydroxyapatite (HAP) chromatography. Approx. 40% of the first strand of the cDNAs were converted to double-stranded structures with a Tm of 88 degrees C. HAP purified double-stranded material was 92% resistant to S1 nuclease. the DNA--DNA reannealing profile of double stranded 32 P-cDNA enriched for the 500 NT band gave a Cot 1/2 of approximately 7 X 10(-4) moles X sec X 1(-1) indicating a complexity for this enriched synthetic gene of 500-600 nucleotide pairs (NTP).
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PMID:Purification of major abundance class of poly(A+)-RNA from rat ventral prostate. 615 88

The major 5'-termini of human adenovirus type 2 early gene block 4 mRNA were sequenced. Poly(A+) polyribosomal RNA was isolated from Ad2 early infected cells, the 5'-terminal m7GPPP removed and the 5'-OH of the penultimate 2'-0-methylated nucleotide labeled with [gamma-32P]ATP using polynucleotide kinase. Ad2 E4 mRNA was purified by hybridization to the Ad2 EcoRI-C fragment and was digested with RNase T1. The resulting oligonucleotides were resolved by two dimensional paper electrophoresis-homochromatography. Four major and 3-4 minor 5'-terminal sequences were identified and characterized. The sequence of the 5'-terminal structures of the major four termini are: (1) m7GpppUmU(m)UUACACUGp, (2) m7GpppUmU(m)UACACUGp, (3) m7GpppUmU(m)ACACUGp, and (4) m7Gppp(m6)AmC(m)ACUGp. These major 5'-terminal sequences were aligned with nucleotide 325, 326, 327, and 329 from the righthand end of the known Ad2 DNA sequence (1) in the region mapped as the 5'-terminus of E4 mRNA by electron microscopy (2,3) and S1 nuclease-gel (4) mapping. Two potential ribosomal binding sites and an initiator codon were found at 40 to 65 nucleotides and about 80 nucleotides, respectively, from these heterogenous 5'-termini. Ad2 E4 major mRNA species appear to be unique since mRNA molecules initiate at a pyrimidine, perhaps by RNA polymerase stuttering, or they are products of an unusual type of RNA processing.
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PMID:Nucleotide sequences and mapping of novel heterogenous 5'-termini of adenovirus 2 early region 4 mRNA. 616 92

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 chromatography on oligo(dT)-cellulose was 20 times more effective as template for cDNA formation than total bacterial RNA, whereas rRNA was inactive. The average chain length of the cDNA was 400 nucleotides (range = 230-800 nucleotides), and 95% of the cDNA could be degraded by the single-strand specific S1 nuclease after denaturation. The small fraction (5%) that was resistant to S1 nuclease may represent duplex hairpin structures. Annealing with poly(A)-RNA protected cDNA from degradation by S1 nuclease, indicating that cDNA indeed contains nucleotide sequences complementary to poly(A)-RNA. These results constitute independent evidence that a large fraction (about 40%) of B. subtilis mRNA is polyadenylated. Moreover, the synthesis of cDNA to bacterial mRNA provides an important new tool for the study of bacterial mRNA structure.
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PMID:The synthesis of DNA complementary to polyadenylate-containing RNA from Bacillus subtilis. 617 11


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