Biosynthesis of a hypermodified nucleotide in Saccharomyces carlsbergensis 17S and HeLa-cell 18S ribosomal ribonucleic acid

1978 ◽  
Vol 171 (3) ◽  
pp. 513.b1-513.b1
Keyword(s):  
Hela Cell ◽  
Ribonucleic Acid ◽  
Saccharomyces Carlsbergensis ◽  
Ribosomal Ribonucleic Acid

scholarly journals Biosynthesis of a hypermodified nucleotide in Saccharomyces carlsbergensis 17S and HeLa-cell 18S ribosomal ribonucleic acid

1978 ◽  
Vol 169 (1) ◽  
pp. 71-77 ◽  
Author(s):  
R C Brand ◽  
J Klootwijk ◽  
R J Planta ◽  
B E H Maden
Keyword(s):  
Hela Cell ◽  
Hela Cells ◽  
Ribonucleic Acid ◽  
18S Rrna ◽  
Saccharomyces Carlsbergensis ◽  
Ribosomal Ribonucleic Acid ◽  
Precursor Molecules

The biosynthesis of a hypermodified nucleotide, similar to or identical with 3-(3-amino-3-carboxypropyl)-1-methylpseudouridine monophosphate, present in Saccharomyces carlsbergensis 17S and HeLa-cell 18S rRNA, was investigated with respect to the sequence of reactions required for synthesis and their timing in ribosome maturation. In both yeast and HeLa cells methylation precedes attachment of the 3-amino-3-carboxypropyl group. In yeast the methylated precursor nucleotide was tentatively characterized as 1-methylpseudouridine. This precursor nucleotide was demonstrated in both 37S and most of the cytoplasmic 18S pre-rRNA (rRNA precursor) molecules. The synthesis of the hypermodified nucleotide is completed just before the final cleavage of 18S pre-rRNA to give 17S rRNA, so that the final addition of the 3-amino-3-carboxypropyl group is a cytoplasmic event. Comparable experiments with HeLa cells indicated that formation of 1-methylpseudouridine occurs at the level of 45S RNA and addition of the 3-amino-3-carboxypropyl group occurs in the cytoplasm on newly synthesized 18S RNA.

scholarly journals Methylated nucleotide sequences in HeLa-cell ribosomal ribonucleic acid. Correlation between the results from ‘fingerprinting’ hydrolysates obtained by digestion with T1 ribonuclease and with T1 plus pancreatic ribonuclease

1977 ◽  
Vol 167 (1) ◽  
pp. 211-221 ◽  
Author(s):  
B E H Maden ◽  
M S N Khan
Keyword(s):  
Hela Cell ◽  
Ribonucleic Acid ◽  
Quantitative Description ◽  
Nucleotide Sequences ◽  
Enzymic Digestion ◽  
Pancreatic Ribonuclease ◽  
Qualitative And Quantitative ◽  
Ribosomal Ribonucleic Acid

The methylated nucleotide sequences in HeLa-cell rRNA were previously characterized after enzymic digestion of the rRNA by T1 ribonuclease alone or by combined T1 plus pancreatic ribonucleases. For any methylated product occurring in a T1-ribonuclease digest there must be one or more corresponding products in a combined T1-plus-pancreatic-ribonuclease digest. Here we correlate fully the inter-relationship between the methylated products occurring in the two digestion systems. The analysis has led to the resolution of some previous uncertainties and has permitted an almost complete qualitative and quantitative description of the methylated components in HeLa-cell rRNA. The data are compared with those reported by other authors for HeLa-cell rRNA.

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