Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DA strain of Theiler's virus causes a chronic progressive demyelination in mice following intracerebral inoculation. Virus was isolated from chronically infected mice, and then grown in cell culture, and the isolates were compared with the parent virus used for inoculation. No defective interfering particles or temperature-sensitive virus were recovered, and capsid proteins appeared identical by SDS-PAGE. One of three isolates had evidence of genomic mutation by Tl ribonuclease oligonucleotide fingerprinting. The significance of these findings with regard to the generation and maintenance of persistence and to adaptation to cell culture is discussed. Also of interest was the marked difference between the DA fingerprint and that of GD VII, a serologically related strain with different biological activity.
J Gen Virol 1983 Mar
PMID:Analysis of Theiler's virus isolates from persistently infected mouse nervous tissue. 629 51

Low doses of u.v. radiation rapidly inactivate poliovirus, and the virus is progressively converted into dense particles (DPs) of buoyant density 1.44 g/ml in CsCl. The DPs are structurally and antigenically related to standard virus (N-antigen), i.e. they are indistinguishable from virus in their RNA and protein content and in their sedimentation properties. Furthermore, there is no difference in reactivity of the structural proteins of virus and DPs with the monofunctional reagent [3H]N-succinimidyl propionate (3H-NSP). However, DPs differ from virus in that their capsids are permeable to several ions, and they can be degraded by RNase and protease. Increasing the radiation dose causes a successive transformation of DPs into 105S slow-sedimenting particles (SSPs). The SSPs are antigenically related to 76S artificial empty capsids (AECs) or H-antigen, but they differ physically and structurally from them. The SSPs have a higher S value than AECs and contain all the capsid proteins, including VP4, and the RNA, both of these macromolecules being absent from AECs. It is concluded, therefore, that transformation from N- to H-antigenicity by u.v. radiation does not require release of RNA and VP4. Conversion of virus particles to SSPs correlates with altered reactivity of VP2 and to a lesser extent VP1 and VP3, with the monofunctional reagent 3H-NSP.
J Gen Virol 1983 Jun
PMID:Dense particles and slow sedimenting particles produced by ultraviolet irradiation of poliovirus. 630 33

DNA copies of segments of Sendai virus genes P, NP and M, obtained by reverse transcription of virus mRNA species extracted from infected cells, were cloned in plasmid pBR322. Genes were identified by hybrid-arrested translation of viral mRNAs in vitro. Hybrid selection of NP mRNA confirmed the identity of an NP gene clone. Partial sequencing of this insert showed that it represents the 5'-terminal region of the gene, containing transcription termination signals. Hybridization of DNA inserts to blots of electrophoretically separated, denatured mRNA species indicated that the P, NP and M messages had sizes of 2400, 2100 and 1500 nucleotides, respectively. Specific T1 ribonuclease-resistant oligonucleotides, previously identified in the NP and M genes, were selected by hybridization to the respective inserts. Although most of the inserts are smaller than 500 base pairs, representing no more than 16% of the P gene and 24% of the NP gene, one of the M gene inserts, comprising 700 base pairs, represents almost half of that gene. These cloned virus gene segments will assist further investigations of the molecular biology of this model paramyxovirus.
J Gen Virol 1983 Aug
PMID:Molecular clones representing Sendai virus genes P, NP and M. 630 32

The use of T1 RNase fingerprinting of terminally labelled genomic double-stranded RNA species from various rotavirus isolates, to analyse the near terminal G-residue positions, has revealed an RNA species-specific fingerprint pattern covering approximately 40 nucleotides at the termini. These RNA species-specific terminal fingerprint patterns were found to be conserved in both rotavirus RNAs isolated from various animal species, and in isolates from a single animal species where gross divergence of internal RNA sequence for a particular RNA species was evident. This conservation of near terminal G-residue positions suggests that, internal to the short regions of absolute terminal sequence conservation that we have previously shown to be present on all rotavirus RNA species, there is a region of conserved sequence which is specific for a particular RNA species.
J Gen Virol 1983 Sep
PMID:The molecular biology of rotaviruses. VI. RNA species-specific terminal conservation in rotaviruses. 631 30

RNase-unfolded chromosomes of competent Bacillus subtilis are able to take up single-stranded homologous donor DNA fragments in vitro to form donor-recipient DNA complexes (Van Randen and Venema 1981). The unfolded chromosomes behave as supercoiled DNA molecules. X-irradiation increased the formation of unstable and stable complexes between donor and recipient DNA during incubation at 37 degrees C. The complex-forming ability of the unfolded chromosomes increased linearly with increasing X-ray dose, even after complete relaxation of the unfolded chromosomes had occurred. Limited DNase I action increased the complex-forming ability of the chromosomes as effectively as X-irradiation. Unstable donor-recipient DNA complexes can be distinguished from stable ones by their dissociation upon density gradient centrifugation in CsCl at pH 11.2. They are stable at pH 10 (Van Randen et al. 1982a). At an intermediate pH value during isopycnic centrifugation, a fraction of the unstable complexes were stable, suggesting that a range of stabilities existed among the unstable complexes. The donor moiety of the stable donor-recipient DNA complexes was far more resistant to nuclease S1 treatment than that of the unstable ones.
Mol Gen Genet 1984
PMID:Involvement of single-strand breaks in complex formation between single-stranded DNA and nucleoids of Bacillus subtilis. 642 34

Some features of the interaction of guanyloribonuclease Sa from Streptomyces aureofaciens with its competitive inhibitor Guo-3'-P were investigated by 1H and 31P NMR spectroscopy. The pH dependence of chemical shifts of C(2)-H protons of the histidine residue of the enzyme were analysed, in the absence and presence of Guo-3'-P. This analysis showed that only one of the two histidines of ribonuclease Sa is located in the active site of the enzyme. 31P NMR resonances of the nucleotide and of its complex with the enzyme indicated that this histidine interacts with the phosphate group of the substrate. The possible relationship between the observed perturbation of the NMR titration curve of the active site of histidine and a conformational change in the enzyme molecule at a pH of approximately 7.5 is also discussed.
Gen Physiol Biophys 1983 Aug
PMID:NMR studies on interactions of ribonuclease Sa with Guo-3'-P. 643 29

The fluorescent dye, diamidinophenylindole-dihydrochloride (DAPI) can be added to CsCl gradients to enhance the density resolution of DNA species, independent of their topological configurations. When Proteus mirabilis and Escherichia coli strains carrying an RP4::Mucts plasmid were examined with the use of such a technique, it was found that after thermal induction of the prophage essentially al of the plasmid DNA became associated with the chromosome. This quantitative association is detergent-RNase- and pronase-resistant and dependent on the expression of Mu genes. The association is temporally, and probably functionally, correlated with the onset of Mu DNA replication. Genetic studies with F'::mini Mu plasmids indicate that some of the association results in stable Hfr formation, and does not require the product of Mu gene B.
Mol Gen Genet 1980
PMID:Fate of plasmids containing Mu DNA: chromosome association and mobilization. 645 Aug 74

Progesterone-specific binding components were detected in the cytosol fraction of enlarged oviducts from estrogen (diethylstilbestrol)-primed immature Japanese quail (Coturnix coturnix japonica) females by several techniques using [3H]promegestone. The oviduct as a target tissue of progesterone is the most efficient in [3H]promegestone binding, and muscle and intestine as nontarget tissues and plasma are less efficient as expected. By using [3H]promegestone for binding, the possibility of blood contamination of the oviduct may have been eliminated with the detection of a specific binding site. The participation of protein in the steroid-binding site was inferred from the destruction of the binding component by protease, but not by RNase or DNase. The interaction with [3H]promegestone in low salt conditions has a high affinity (Kd 0.69 nM) and low capacity (the number of binding sites per milligram of protein is about 1.3 pmol). Six unlabeled steroids were tested as competitors for binding to [3H]promegestone in vitro. Progesterone-like steroids competed specifically with [3H]promegestone: progesterone congruent to promegestone greater than deoxycorticosterone greater than testosterone much greater than estradiol-17 beta greater than cortisol. These chemical properties show that the progesterone binding protein present in the oviduct of estrogen-primed quail is essentially similar to that obtained from chick oviduct. In addition, heterogeneity of the [3H]promegestone binding components was shown. The binding component was eluted as an aggregate on gel (Bio-Gel A-0.5m) column chromatography in low salt conditions which reverted to two major peaks, tentatively named I (molecular weight, about 110,000) and II (about 41,000), in the presence of high salt (0.3 M KCl). The relative amounts of the two peaks differed. It was interesting that peak II of the small component was not found in the estrogen-primed chick and was a distinctive one in quail. On the other hand, both peaks were recovered with 0.3 M KCl elution on DEAE-cellulose column chromatography. These studies suggest that this binding component may function as a biological receptor for progesterone in the estrogen-enlarged oviduct, and the problems to be solved are under examination.
Gen Comp Endocrinol 1984 Jan
PMID:Binding of progesterone with the oviduct cytosol fraction of estrogen-primed quail (Coturnix coturnix japonica). 653 58

The binding of [6,7-3H]triamcinolone acetonide (TA) to intestinal mucosa of freshwater-adapted silver eels was studied. The cytoplasmic preparations bound the ligand with an equilibrium dissociation constant (KD) of 2.28 +/- 0.37 nM and the maximal number of binding sites (Nmax) was 960 +/- 55 fmol/mg of protein (+/- SE, n = 13). Scatchard analysis indicated the presence of a single species of binding sites. Binding was abolished following treatment of the cytosol with trypsin, N-ethylmaleimide, or Mersalyl, but DNase or RNase treatment had little effect. The competition hierarchy of radioinert steroids on the formation of the [3H]TA-receptor complex was TA greater than dexamethasone greater than cortisol greater than 11-deoxycortisol. Aldosterone, DOC, corticosterone, 11-dehydrocorticosterone, progesterone, testosterone, or estradiol-17 beta did not compete. Sedimentation of the [3H]TA-receptor complex on a linear sucrose gradient (10-30% + 10% v/v glycerol) yielded single peaks in the absence or presence of 0.4 M KCl in the gradient (6 S or 3.5 S respectively). Following heat activation the receptor-ligand complex was freely translocated to homologous nuclei in vitro, though the activated complex did not bind to DNA-cellulose. It was concluded that the eel intestinal mucosal cytosol contains a high-affinity-low capacity steroid receptor system. This is the first instance that such a system was demonstrated in fish tissue.
Gen Comp Endocrinol 1983 Aug
PMID:Intestinal triamcinolone acetonide receptors of the eel (Anguilla rostrata). 661 55

The presence of glucocorticoid-binding macromolecular receptors was demonstrated in the Na2MO4 (10 mM)-stabilized gill cytosol of the American eel, Anguilla rostrata and in that of the trout, Salmo gairdneri. In all experiments, tritiated triamcinolone acetonide [( 3H]TA) was used as ligand. In the eel, the steroid was bound with a KD of 2.84 +/- 0.4 nM and an Nmax of 188 +/- 34 fmol/mg protein. The binding parameters for the trout cytosol were KD = 1.43 +/- 0.13 nM; Nmax = 271 +/- 113 fmol/mg protein. Competition studies with [3H]TA-labeled eel gill cytosol and radioinert steroids gave the following binding hierarchy: TA greater than dexamethasone greater than cortisol greater than 11-deoxycortisol greater than 21-deoxycortisol. Aldosterone, estrogens, or androgens did not complete. The eel gill receptor was deactivated by prior treatment with trypsin or mersalyl. RNase was without effect, but DNase degraded the receptor except when used in the presence of trypsin inhibitor. The eel gill TA-receptor complex sedimented on a linear (10-30%) sucrose gradient with a single peak at 7.0 S or 3.5 S, in hypotonic or hypertonic (0.4 M KCl) gradients, respectively. The eel ligand-receptor complex did not bind, following heat activation, to DNA-cellulose or phospho-cellulose, though it bound to DEAE-cellulose. In this respect, it behaved similarly to the eel intestinal mucosal TA-receptor complex, described previously. The initiation of dissociation of the eel receptor-[3H]TA complex with excess TA yielded pseudo-first-order dissociation kinetics (k-1 at 0 degree C: 2.39 X 10(-5) S-1), while the association kinetics of the receptor with the ligand was of second order (k + 1: 2.51 X 10(4) M-1 S-1). Sepharose column chromatography indicated a molecular weight of 334,690 Da. Calculation of the Stokes radius gave a value of 84.5 A and the frictional ratio, calculated from the molecular weight, was 1.84. From these data it was concluded that the gills of these two euryhaline teleosts contain tetrapod-type glucocorticoid receptors. These studies are the first to demonstrate these steroid recognition molecules in fish gill. The presence of receptors in the fish gill tissue are in agreement with the physiological action of corticosteroids in allowing adaptation of the animals to habitats of different salinity.
Gen Comp Endocrinol 1984 Mar
PMID:Glucocorticoid receptors in the gill tissue of fish. 671 55


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