Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The functionally active fragments MS2 R(-53 leads to 6) and MS2 R(-53 leads to 3) comprising the regulatory region for the replicase cistron have been isolated from MS2 RNA-coat protein complex following T1 RNase digestion. In order to obtain shorter fragments, active in coat protein binding and initiation of translation, MS2 R(-53 leads to 6) was cleaved with S1 nuclease. The results indicate that S1 nuclease attacks the most susceptible loop regions of the two hairpin helices of MSZ R(-53) leads to 6). Among the three fragments which have been isolated, only MS2 R(-35/33 leads to 6) containing the intact hairpin (b) region with initiation codon AUG is active in the coat protein binding. Functional activity exerted by another polynucleotide MS R(-17 leads to 6) supports the assumption that specific binding with the coat protein is determined by the hairpin (b) region prior to the replicase cistron.
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PMID:The regulatory region of MS2 phage RNA replicase cistron. III. Characterization of fragments resulting from S1 nuclease digestion. 10 12

Several in vitro properties of partially purified form II RNA polymerase from Drosophila melanogaster embryo nuclei are described. The enzyme preparation is free from contaminating RNase, protein kinase, and polyphosphate kinase activities and can be used to study the incorporation of gamma-32P-labeled nucleoside triphosphates. The enzyme exhibits a biphasic heat inactivation pattern which is probably related to differential lability of its two subforms. However, a considerable protection against heat inactivation is provided by the nucleoside triphosphates present in the in vitro reaction system such that the enzyme catalyzes RNA synthesis in a nearly linear mode for over 2 hr at 30 C. Two initiation inhibitors, rifamycin AF/013 was found unsuitable for critical studies because of the high concentrations necessary for total inhibition (200 micrograms/ml) and particularly because of the obligate use of solvents which secondarily have a destabilizing effect on native DNA. Poly[I] was found to effectively block initiation at very low concentrations (1 microgram/ml). The enzyme rapidly forms poly[I]-resistant preinitiation complexes on both double- and single-stranded DNA. These complexes decay with a half-life of 2.5--3 min. RNA synthesis from poly[I]-resistant complexes amounts to 10% of the total potential synthesis on both double- and single-stranded DNA. Enzyme-DNA saturation experiments indicate that the form II enzyme discriminates two types of sites on Drosophila DNA, tight binding and weak binding, from which RNA synthesis proceeds slowly and rapidly, respectively. The tight-binding sites appear to be analogous to those sites with which the enzyme is able to form poly[I]-resistant complexes.
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PMID:Form II DNA-dependent RNA polymerase from Drosophila melanogaster: general in vitro catalytic properties and template interactions. 11 Mar 17

Ribonucleic acid extracts of lymphoid cells from immune hosts were used to transfer in vivo and in vitro cell-mediated immune reactivity to a variety of antigens. The in vivo immune responses transferred by RNA included the delayed cutaneous hypersensitivity reaction to fungal and chemically-defined antigens and the tumor-rejection reaction to guinea pig hepatoma antigens. The in vitro immune responses transferred by RNA included macrophage migration inhibition by fungal, chemically-defined, and tumor antigens. The transfer activity of RNA preparations was contained in the 8 s to 18 s species of RNA and was sensitive to RNase but not to DNase or trypsin. Antigen was not detectable in the RNA preparations and appeared to have no role in the transfer activity. Syngeneic, allogeneic, or xenogeneic sources of RNA could transfer immune reactivity. In each system tested, the transfer of cell-mediated reactivity by RNA was specific for the antigen used to sensitize the RNA donor. The potential use of RNA-mediated transfer of immunity is discussed.
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PMID:Some perspectives on the transfer of cell-mediated immunity by immune-RNA. 11 79

Staring from low molecular weight RNA obtained from rainbow trout (Salmo gairdnerii) liver, 5S ribosomal RNA (rRNA) was highly purified by successive chromatography on columns of DEAE-Sephadex A50 and Sephadex G100. Products of complete and partial digestions on this RNA with pancreatic ribonuclease (RNase A) [EC 3.1.4.22] and RNase T [EC 3.1.4.8] were isolated and sequenced by conventional and high-performance liquid chromatography (HPLC) procedures. The nucleotide sequence of this RNA thus established was compared with those of five other vertebrae 5S rRNAs, and the rates of base substitution per site per year were found to be nearly constant in these RNAs. The analyses of the partial digests of the trout 5S rRNA revealed several sites susceptible to RNase attack, which could be accounted for by the secondary structure model for eukaryotic 5S rRNAs proposed by Nishikawa and Takemura (1).
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PMID:Nucleotide sequence of 5S ribosomal RNA from rainbow trout (Salmo gairdnerii) liver. 11 50

Conditions were established for the separation and quantitative determination of ribonucleosides, mono- and oligo-ribonucleotides by high-performance liquid chromatography (HPLC) on columns of AS-Pellionex SAX and AL-Pellionex WAX. By combining a high-speed UV spectrum monitor with an HPLC apparatus, products of RNase digestions of oligonucleotides and 5S ribosomal RNA (rRNA) were identified by measuring their UV spectra under continuous solvent flow, and also from their retention times on the columns (positions of elution). It took only 10 to 30 min for one chromatography run and required less than 0.01 A260 unit of sample per nucleotide material in each peak.
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PMID:Methods for sequencing oligoribonucleotides and RNA by high performance liquid chromatography. 11 51

The sequences of the first 17 nucleotides of cowpea mosaic virus middle and bottom RNAs adjacent to the covalently-linked proteins have been determined. Sequences of the oligonucleotides, produced by complete T1 RNase digestion, were established after labelling of the 3' termini in vitro using RNA ligase. Both sequences are A/U-rich, the first nine nucleotides being identical.
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PMID:Nucleotide sequences adjacent to the proteins covalently linked to the cowpea mosaic virus genome. Sequence determination after labelling in vitro using RNA ligase. 11 52

To refine the secondary structure model of the 5' end of the bacteriophage MS2 genome, 32P-labeled MS2 RNA was partially digested with T1 RNase or with Cm-RNase and the 5'-end fragment was isolated, renatured and submitted to treatment with methoxyamine or kethoxal. The resulting modified RNA was digested with T1 RNase and the products were separated by minifingerprinting. Methoxyamine-induced modification of exposed cytidines was detected by differential mobility of modified oligonucleotides, while kethoxal-induced alteration of exposed guanosines was monitored by resistance to T1 ribonuclease digestion. The positions of the modified residues are discussed in terms of an improved secondary structure model proposed for the 5' end of the viral RNA. The structure itself is discussed in relation to sequence conservation and biological function.
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PMID:Secondary structure of the 5' end of bacteriophage MS2 RNA Methoxyamine and kethoxal modification. 11 78

A cytoplasmic component from group A streptococci produced complete suppression of human lymphocyte transformation induced by phytohaemagglutinin or the mixed lymphocyte reaction in vitro. It also suppressed antibody-forming cells in mice against sheep erythrocytes. The active substance was eluted as second and third fractions form Sephadex G-200 chromatography of the 100,000 g supernatant of sonically ruptured group A streptococci. The antimitogenic activity was not susceptible to trypsin, pronase, RNase or DNase digestion, but the activity was completely lost when it was sequentially digested, first with RNase and DNase and then with pronase. The active substance was not antigenic nor heat-labile at 56 degrees. It may be a protein component of a nucleoprotein.
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PMID:A potent antimitogenic factor from group A streptococci. 12 16

The effect of purified wild-type RNA (allo-RNA) on genetic reversion of inositol-requiring mutant 89601 of Neurospora crassa is described. The mutant (inos minus) strain, on treatment with the wild-type RNA preparation, was found to revert to wild type (inos+) in significant numbers. RNA from the mutant (iso-RNA) and allo-RNA digested by RNase were ineffective in causing genetic reversion at the inositol locus. The allo-RNA-induced revertants were stable and showed a Mendelian transmission of the inos+ character.
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PMID:Induction by RNA of inositol independence in Neurospora crassa. 12 44

In order to increase the efficiency of different mRNAs from wheat seedlings in carrying out cell-free protein synthesis in the wheat system, efforts were made to remove endogenous mRNA. In this direction, we checked the possibility of using immobilized RNase. Treatment of the cell-free system or its components with this enzyme caused a large decrease in the efficiency of poly tu-directed incorporation of labeled amino acids. This effect did not coincide with an equivalent degradation of RNA, as has been shown by analysis of ribosomes and polysomes. The results are discussed in the light of recent findings of some authors.
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PMID:[Influence of immobilized ribonuclease on the cell-free protein synthesis in the wheat system (author's transl)]. 12 68


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