Demonstration of ribosome-dependent photoinduced chain breakage of the 16S ribosomal ribonucleic acid component of the Escherichia coli 30S ribosomal subunit

Biochemistry ◽  
1976 ◽  
Vol 15 (25) ◽  
pp. 5474-5480 ◽  
Author(s):  
Lester Gorelic
Keyword(s):  
Escherichia Coli ◽  
Ribonucleic Acid ◽  
Ribosomal Subunit ◽  
Acid Component ◽  
Ribosomal Ribonucleic Acid

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 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.

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