5S Ribonucleic Acid in Ribosomes from Mammalian Tissues

1. A method for the extraction of plant nucleic acids and their separation on methylated-serum-albumin-kieselguhr columns is described. It is demonstrated that the characteristics of the elution profiles of material from the same source are consistently reproducible. 2. Major dissimilarities were found in the elution profiles of nucleic acids from root and from leaves of Vicia faba L. These dissimilarities were confirmed by polyacrylamide-gel electrophoresis. 3. Four distinct types of low-molecular-weight RNA were demonstrated to be present in leaves, clearly distinguished by their behaviour when chromatographed on methylated-serum-albumin-kieselguhr columns. (a) Both cytoplasmic and chloroplast ribosomes contained a low-molecular-weight RNA, and these components were distinct from each other. (b) The chloroplast possessed a unique ;soluble' RNA (i.e. RNA that is not precipitated by centrifugal forces that sediment ribosomes) which was not present in the rest of the cell. (c) A soluble component, probably transfer RNA, was found in both the chloroplasts and in the cytoplasm. 4. The components distinguishable by methylated-serum-albumin-kieselguhr column chromatography could not be distinguished by sucrose-density-gradient centrifugation.

Section: Resultssupporting

confidence: 53%

Chloroplast and cytoplasmic low-molecular-weight ribonucleic acid components of the leaf of Vicia faba L.

Dyer

Leech

1968

“…Ribosomal subunits were separated in sucrose gradients (a). The RNA of the larger (b) and smaller (c) subunit was fractionated in 7.5% polyacrylamide gels at 7 V/cm length of gel for 3 h. mined for 5 S RNA isolated from rat liver (Bachvaroff & Tongur, 1966), E. coli (Boedtker & Kelling, 1967) and Blastocladiella emersonii (Comb & Zehavi-Willner, 1967).…”

Section: Localization Of Cytoplamic and Chloropla8t 5smentioning

confidence: 99%

Characterization of cytoplasmic and chloroplast 5S ribosomal ribonucleic acid from broad-bean leaves

Payne

Dyer

1971

Green leaves of the broad bean (Vicia faba) contain two 5S RNA components that can be separated from each other by polyacrylamide-gel electrophoresis. The major component is located in the larger subunit of cytoplasmic ribosomes, whereas the minor component occurs in the larger subunit of chloroplast ribosomes. Their electrophoretic mobilities relative to those of Escherichia coli 5S RNA (120 nucleotides) and plant 4S RNA (78 nucleotides) suggest that they consist of 118 and 122 nucleotide residues respectively. Thermal ;melting' profiles of plant cytoplasmic and chloroplast 5S RNA species at 260nm indicate the similarity of their secondary structures, not only to each other, but also to those of E. coli and mammalian 5S RNA species. The base compositions of the two plant 5S RNA species have more in common with each other than with the corresponding molecules from either E. coli or mammalian cells.

“…The second structural RNA component, 5S RNA, of the larger subparticle (Rosset, Monier & Julien, 1964;Bachvaroff & Tongur, 1966;Forget & Weissman, 1967;Brownlee, Sanger & Barrell, 1968) becomes attached to the larger subparticle at a late stage in the maturation of the ribosome and then remains in permanent association (Kaempfer & Me4elson, 1968). The 5s RNA remains attached to the larger subparticle even after 20% of the protein is removed, but is liberated when more protein is lost or on titration with EDTA (Morell & Marmur, 1968; see also Comb.…”

Section: Role Of 5 S Rnamentioning

confidence: 99%

A possible structure of the rabbit reticulocyte ribosome. An exercise in model building

Cox

Bonanou

1969

It is suggested that the location of each of the diverse ribosomal proteins in the ribosome, or in the ribosomal subparticles in their native or derived forms, is determined by the nucleotide sequence of the 16s and 23-30s RNA moieties, i.e. that the 16s and 23-30s RNA species provide a unique binding site for each species of ribosomal protein. The ways of assembling such a thread into a ribosome-like structure appear limited if the ribosome is largely stabilized by protein-protein interactions. The nucleoprotein thread was built into a structure, having the general features of a hollow cylinder, that is consistent with the known dimensions and properties of the rabbit reticulocyte ribosome. It appears possible to test the model by experiment.