scholarly journals Identical 3′-terminal octanucleotide sequence in 18S ribosomal ribonucleic acid from different eukaryotes. A proposed role for this sequence in the recognition of terminator codons

1974 ◽  
Vol 141 (3) ◽  
pp. 609-615 ◽  
Author(s):  
John Shine ◽  
Lynn Dalgarno
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Ribonucleic Acid ◽  
18S Rrna ◽  
Base Sequence ◽  
Terminal Sequence ◽  
Ribosomal Ribonucleic Acid ◽  
Rrna Species

The 3′-terminal sequence of 18S ribosomal RNA from Drosophila melanogaster and Saccharomyces cerevisiae was determined by stepwise degradation from the 3′-terminus and labelling with [3H]isoniazid. The sequence G-A-U-C-A-U-U-AOH was found at the 3′-terminus of both 18S rRNA species. Less extensive data for 18S RNA from a number of other eukaryotes are consistent with the same 3′-terminal sequence, and an identical sequence has previously been reported for the 3′-end of rabbit reticulocyte 18S rRNA (Hunt, 1970). These results suggest that the base sequence in this region is strongly conserved and may be identical in all eukaryotes. As the 3′-terminal hexanucleotide is complementary to eukaryotic terminator codons we discuss the possibility that the 3′-end of 18S rRNA may have a direct base-pairing role in the termination of protein synthesis.

scholarly journals Studies on the 3′-terminal sequences of the large ribosomal ribonucleic acid of different eukaryotes and those associated with ‘hidden’ breaks in heat-dissociable insect 26S ribonucleic acid

1974 ◽  
Vol 141 (3) ◽  
pp. 617-625 ◽  
Author(s):  
John Shine ◽  
John A. Hunt ◽  
Lynn Dalgarno
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Ribonucleic Acid ◽  
Galleria Mellonella ◽  
Terminal Sequence ◽  
6S Rna ◽  
Ribosomal Ribonucleic Acid ◽  
Higher Eukaryotes ◽  
26S Rrna ◽  
Polynucleotide Chain

The 3′-terminal sequences associated with the large rRNA complex from a range of eukaryotes were determined after pancreatic or T1-ribonuclease digestion of RNA terminally labelled with [3H]isoniazid. In all higher eukaryotes examined except Drosophila melanogaster, the 3′-terminal sequences Y-G-UOH and G-C-UOH were demonstrated for the large RNA component(s) and for 6S RNA respectively. The 3′-terminal sequence of Saccharomyces cerevisiae 26S RNA was Y-G-UOH and that of 6S RNA Y-A-U-U-UOH. Three 3′-terminal sequences were found in equimolar amounts in the heat-dissociable 26S rRNA characteristic of insect ribosomes. These were Y-G-U-G-UOH, Y-C-G-UOH and G-C-UOH for cultured Antheraea eucalypti cells, Y-G-UOH, Y-G-UOH and G-C-UOH for Galleria mellonella larvae and Y-C-G-AOH, Y-G-U-AOH and G-Y-U-GOH for Drosophila melanogaster flies. Thus the introduction of the central scission in insect 26S rRNA results in the generation of a unique 3′-terminus and does not arise from random cleavage of the polynucleotide chain.

The ribosomes of Plasmodium berghei: isolation and ribosomal ribonucleic acid analysis

Parasitology ◽  
1978 ◽  
Vol 77 (3) ◽  
pp. 345-366 ◽  
Author(s):  
F. W. Miller ◽  
Judith Ilan
Keyword(s):  
Plasmodium Berghei ◽  
Ribonucleic Acid ◽  
Ribosomal Subunit ◽  
High Yield ◽  
Small Component ◽  
40S Ribosomal Subunit ◽  
Ribosomal Ribonucleic Acid ◽  
Rrna Species ◽  
Specific Degradation ◽  
Triton X

SummaryRibosomes and high molecular weight ribosomal ribonucleic acid (rRNA) from the blood stages of Plasmodium berghei parasites were studied in preparations free from host ribosome contamination. Purified malarial ribosomes were isolated in high yield from a population of ultrastructurally intact, viable parasites by hypertonic lysis with Triton X-100 and differential centrifugation. These ribosomes were shown to be derived from active polysomes and could be dissociated into subunits by puromycin–0·5 m KCl treatment. Malarial rRNA extracted from purified 40S and 60S ribosomal subunits was characterized by electrophoretic, sedimentation and base ratio analyses. Like certain other protozoa, the P. berghei 40S ribosomal subunit possessed an exceptionally large RNA species (mol. wt 0·9 × 106), while RNA isolated from the parasite's 60S subunit (mol. wt 1·5 × 106) was specifically ‘nicked’ to produce one large component (mol.wt 1·2 × 106) and one small component (mol.wt 0·3 × 106) in equimolar quantities. These rRNA's migrate identically on polyacrylamide gels after heating to 63°C for 5 mm or under denaturing conditions in the presence of formamide, indicating an absence of aggregation and non-specific degradation of the rRNA species. Base composition studies showed P. berghei rRNA to be low in guanosine and cytosine content, as is the case for protozoa generally.

scholarly journals The binding of spermine to the ribosomes and ribosomal ribonucleic acid from Bacillus stearothermophilus

1969 ◽  
Vol 113 (1) ◽  
pp. 117-121 ◽  
Author(s):  
L. Stevens
Keyword(s):  
Ionic Strength ◽  
Ribosomal Rna ◽  
Ribonucleic Acid ◽  
Binding Sites ◽  
Bacillus Stearothermophilus ◽  
Gel Filtration ◽  
Ribosomal Ribonucleic Acid ◽  
Number Of Binding Sites ◽  
Filtration Technique

1. The total intracellular concentrations of Na+, K+, Mg2+, spermine, spermidine and RNA were measured in Bacillus stearothermophilus. 2. The binding of spermine to ribosomes and to ribosomal RNA from B. stearothermophilus was studied under various conditions by using a gel-filtration technique. 3. The affinity of spermine for ribosomes and for ribosomal RNA decreased with increasing ionic strength of the medium in which they were suspended. 4. The extent of spermine binding did not change appreciably in the temperature range 4–60°. 5. Optimum binding occurred at about pH7·0. 6. The number of binding sites for spermine on either ribosomes or ribosomal RNA was 0·10–0·13/RNA phosphate group. 7. A high proportion of the intracellular spermine is likely to be bound to the ribosomes in vivo; spermine competes with Mg2+ on equal terms for sites on the ribosomes.

scholarly journals Dual pathways for ribonucleic acid turnover in WI-38 but not in I-cell human diploid fibroblasts.

1981 ◽  
Vol 1 (1) ◽  
pp. 75-81 ◽  
Author(s):  
M Sameshima ◽  
S A Liebhaber ◽  
D Schlessinger
Keyword(s):  
Ribosomal Rna ◽  
Ribonucleic Acid ◽  
Protein Turnover ◽  
Rna Turnover ◽  
Turnover Rates ◽  
Diploid Fibroblasts ◽  
Human Diploid Fibroblasts ◽  
Cytoplasmic Rna ◽  
Ribosomal Ribonucleic Acid ◽  
I Cells

The turnover rates of 3H-labeled 18S ribosomal ribonucleic acid (RNA), 28S ribosomal RNA, transfer RNA, and total cytoplasmic RNA were very similar in growing WI-38 diploid fibroblasts. The rate of turnover was at least twofold greater when cell growth stopped due to cell confluence, 3H irradiation, or treatment with 20 mM NaN3 or 2 mM NaF. In contrast, the rate of total 3H-protein turnover was the same in growing and nongrowing cells. Both RNA and protein turnovers were accelerated at least twofold in WI-38 cells deprived of serum, and this increase in turnover was inhibited by NH4Cl. These results are consistent with two pathways for RNA turnover, one of them being nonlysosomal and the other being lysosome mediated (NH4Cl sensitive), as has been suggested for protein turnover. Also consistent with the notion of two pathways for RNA turnover were findings with I-cells, which are deficient for many lysosomal enzymes, and in which all RNA turnover was nonlysosomal (NH4Cl resistant).

scholarly journals Deoxyribonucleic acid–ribonucleic acid hybridization. Annealing and quantitative recovery of intact ribosomal ribonucleic acid molecules from hybrids

1969 ◽  
Vol 115 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Michael Fry ◽  
Michael Artman
Keyword(s):  
Ribosomal Rna ◽  
Ribonucleic Acid ◽  
Messenger Rna ◽  
Deoxyribonucleic Acid ◽  
Cellulose Nitrate ◽  
Absolute Size ◽  
Rna Molecules ◽  
Membrane Filters ◽  
Ribosomal Ribonucleic Acid

A simple and efficient method for hybridization and subsequent recovery of non-fragmented ribosomal RNA from the hybrid is described. The procedure involves annealing of immobilized denatured DNA bound on cellulose nitrate membrane filters to complementary RNA in 50% (v/v) formamide–0·33m-potassium chloride–10mm-tris–hydrochloric acid buffer, pH7·4, at 33° for 3hr. Under these conditions no detectable changes in the sedimentation coefficients of the input RNA were detected. The RNA can subsequently be recovered quantitatively from the hybrid in intact form by incubating the filters in formamide or in 85% (v/v) dimethyl sulphoxide. The applicability of the method for the evaluation of the absolute size of ribosomal RNA cistrons in Escherichia coli DNA and for the determination of the size of messenger RNA molecules is discussed.

scholarly journals Higher-plant mitochondrial ribosomes contain a 5S ribosomal ribonucleic acid component

1976 ◽  
Vol 157 (1) ◽  
pp. 275-277 ◽  
Author(s):  
C J Leaver ◽  
M A Harmey
Keyword(s):  
Ribonucleic Acid ◽  
Plant Mitochondria ◽  
5S Rrna ◽  
Higher Plant ◽  
Acid Component ◽  
Mitochondrial Ribosomes ◽  
Ribosomal Ribonucleic Acid ◽  
Rrna Species ◽  
Hydrogen Bonded

Ribosomes from higher-plant mitochondria contain 5S rRNA, in contrast with the mitochondrial ribosomes of animals and fungi, in which such a component has not been detected. In common with the ribosomes of prokaryotes and chloroplasts, higher-plant mitochondrial ribosomes do not appear to contain an RNA equivalent to the 5.8 S rRNA that is found in eukaryoytes hydrogen-bonded to the largest of the cytoplasmic rRNA species.

Relaxed mutant of Saccharomyces cerevisiae: Proper maturation of ribosomal RNA in absence of protein synthesis

Cell ◽  
1983 ◽  
Vol 33 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Liliana Waltschewa ◽  
Oleg Georgiev ◽  
Pencho Venkov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Ribosomal Rna

Hypermodified alkali-stable dinucleotide sequences in each of the high-molecular-weight (26S and 18S) ribosomal RNA species of wheat

1977 ◽  
Vol 55 (5) ◽  
pp. 582-586 ◽  
Author(s):  
M. W. Gray ◽  
R. S. Cunningham
Keyword(s):  
Molecular Weight ◽  
Ribosomal Rna ◽  
18S Rrna ◽  
28S Rrna ◽  
Animal Cells ◽  
Wheat Embryo ◽  
Rrna Species ◽  
Wheat Embryos ◽  
The Individual ◽  
26S Rrna

Two hypermodified, alkali-stable dinucleotide sequences, each containing abase modification in addition to sugar methylation, are known to be present in wheat embryo 26S + 18S rRNA (Gray, M. W. (1974) Biochemistry 13, 5453–5463). Quantitative analysis of unfractionated 26S + 18S rRNA had suggested that each of these sequences (Cm-ψp and ψm-Ap, where Cm = O2′-methylcytidine and ψm = O2′-methylpseudouridine) was present in either the 18S or the 26S rRNA species, but not in both, at a frequency of not more than once per chain. In the study reported here, the individual 32P-labeled 18S and 26S rRNA species were isolated from viable wheat embryos germinated in the presence of [32P]orthophosphate. From analyses of phosphodiesterase and alkaline hydrolysates of the separated [32P]RNAs, we conclude that ψm-Ap is confined to wheat cytosol 18S rRNA, whereas Cm-ψp is localized in wheat cytosol 26S rRNA. The presence of ψm in the 18S rRNA of wheat stands in contrast with the situation in animal cells, where this hypermodified nucleoside is located in the 28S rRNA (Khan, M. S. N. &Maden, B. E. H. (1976) J. Mol. Biol. 101, 235–254)

scholarly journals A spectrophotometric study of the secondary structure of precursor ribosomal ribonucleic acid from Krebs ascites-tumour cells

1973 ◽  
Vol 135 (2) ◽  
pp. 349-351 ◽  
Author(s):  
A. A. Hadjiolov ◽  
R. A. Cox
Keyword(s):  
Secondary Structure ◽  
Ribonucleic Acid ◽  
18S Rrna ◽  
Spectrophotometric Study ◽  
Spectrophotometric Analysis ◽  
28S Rrna ◽  
Ascites Tumour ◽  
Helical Content ◽  
Ribosomal Ribonucleic Acid ◽  
Ascites Tumour Cells

The spectrophotometric analysis of 45S precursor rRNA shows that it contains more G and C residues than does mature 28S or 18S rRNA. The helical content and the length of double-helical segments in 45S and 28S rRNA are similar.

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