Showing papers on "Ribosomal protein published in 1971"
158 citations
TL;DR: It was concluded that a primary effect of colicin E3 is the activation of a highly specific RNase that degrades 30S ribosomal RNA in situ, and that the resulting fragment(s) are probably retained within the 30S particle.
Abstract: The properties of 30S ribosomal subunits from untreated and from colicin E3-treated (E3-30S) bacteria have been compared. Polyacrylamide gel electrophoresis of ribosomal proteins revealed no difference, but several studies indicated that the 16S RNA from E3-30S particles was modified. E3-16S RNA showed slightly increased resistance to heat-induced degradation and had a reduced (15 S) sedimentation coefficient on sucrose gradients. Fingerprint analyses of E3-16S RNA revealed that the 3′-terminus of the molecule had been deleted. It was concluded that a primary effect of colicin E3 is the activation of a highly specific RNase that degrades 30S ribosomal RNA in situ, and that the resulting fragment(s) are probably retained within the 30S particle.
156 citations
TL;DR: Ribosomal proteins isolated from 30S subunits of E. coli in four laboratories have been correlated by using two-dimensional gel electrophoresis, immunological techniques, amino acid compositions and molecular weights.
Abstract: Ribosomal proteins isolated from 30S subunits ofE. coli in four laboratories have been correlated by using two-dimensional gel electrophoresis, immunological techniques, amino acid compositions and molecular weights. The results are given in the Table. A common nomenclature for naming 30 S ribosomal proteins and their genetic loci is proposed.
151 citations
150 citations
145 citations
TL;DR: This work has shown that during each step of peptide chain elongation the ribosome shifts up one triplet along the messenger RNA with concomitant movement of the peptidyl-transfer RNA from the donor to the acceptor site.
Abstract: DURING each step of peptide chain elongation the ribosome shifts up one triplet along the messenger RNA with concomitant movement of the peptidyl-transfer RNA from the donor to the acceptor site. This process, commonly known as translocation, is triggered by a supernatant protein, factor G, which in association with the ribosome cleaves GTP into GDP and inorganic phosphate1,2 and it has been argued that the energy liberated in this reaction is used “to carry the complex one triplet forward”3.
123 citations
TL;DR: The number of rabbit reticulocyte ribosomal proteins resolved by a new method of two-dimensional polyacrylamide gel electrophoresis closely approaches the total number in the ribosome, with an estimate of the molecular weight of all 63 resolved proteins.
120 citations
TL;DR: Both ribosomal subunits undergo distinct changes in their sedimentation rate, concomitant with the loss of their biological activity, when sedimented into sucrose gradients containing high concentrations of monovalent ions and low concentrations of magnesium.
Abstract: 5S RNA is removed from the large ribosomal subunit of both rat liver and rabbit reticulocyte ribosomes by treatment with EDTA to remove magnesium ions. The RNA is removed not as a naked molecule, but in association with a single ribosomal protein (molecular weight about 35,000) as a ribonucleoprotein, sedimenting at about 7 S. Conditions for the exclusive removal of the 5S RNA-protein complex have been established.
Both ribosomal subunits undergo distinct changes in their sedimentation rate, concomitant with the loss of their biological activity, when sedimented into sucrose gradients containing high concentrations of monovalent ions and low concentrations of magnesium. Under these conditions the large subunit loses 5S RNA, the 5S RNA-associated protein, and several more proteins.
117 citations
TL;DR: This finding validates the attempt to use a simple, genetically tractable organism, the yeast, to study the general problem of nucleocytoplasmic interactions in eukaryotes.
112 citations
TL;DR: The mutation in the strain Sp-49-1 responsible for the cold-sensitive and ribosome assembly defective phenotypes was characterized and the altered protein component was identified as the 30 s ribosomal protein P4, the protein studied previously in spectinomycin-resistant mutant.
111 citations
TL;DR: It is concluded that no significant common sequences exist among any of the 21 30S ribosomal proteins of E. coli.
Abstract: Antisera specific for each of the 21 homogenous ribosomal proteins from 30S subunits of Escherichia coli were used to investigate, by immunodiffusion and immunoprecipitation, whether there are any extensive sequence homologies among these proteins. No immunological crossreactions were detected between any of the proteins. Therefore, we conclude that no significant common sequences exist among any of the 21 30S ribosomal proteins of E. coli.
TL;DR: Two protein kinases can be prepared from rat liver supernatant by catalyzing phosphorylation of ribosomal proteins is stimulated by cyclic AMP.
TL;DR: The functional peculiarities of ram mutants correlate with an observed alteration in chromatographic mobility of P4(a), a specific protein of the 30S ribosomal subunit, and the known location of the ram mutational site in the vicinity of other 30S genetic determinants suggest that ram is the structural gene for P 4(a).
Abstract: The functional peculiarities of ram mutants correlate with an observed alteration in chromatographic mobility of P4a, a specific protein of the 30S ribosomal subunit. This finding is supported by ribosomal reconstitution experiments. These facts, together with the known location of the ram mutational site in the vicinity of other 30S genetic determinants, suggest that ram is the structural gene for P4a.
The known contrasting roles of ram and strA in determining translational efficiency require that the function of P4a should be explained in relation to P10 (the 30S-subunit protein defined by strA). One consequence of altering P4a, a key protein in ribosome assembly, might be to change the interaction of P10 with the 30S subunit. The functional interrelationship of P4a and P10 is discussed in terms of the possible roles of these two proteins in regulating access of tRNA molecules to the decoding site.
TL;DR: It is suggested that 2b is the N-ethyl maleimide-sensitive protein in the ribosome, which becomes insensitive to N-methylmaleimide inactivation when the iodoacetamide reaction has proceeded to the point where 2B is no longer available for reaction.
TL;DR: The method was used to determine the pI's of the protein of E. coli ribosomes, and it is shown that eleven of the 30S and ten of the 50S proteins have pI values ≧12.0, whereas seven of the30S and fifteen of the50S proteins has pI’s of less than 12.0.
TL;DR: The increased protein content of eucaryotic ribosomes, as compared with bacterial, is explained both by the presence of a greater number of moles of protein and by proteins of larger average size.
TL;DR: It is concluded that the proteins investigated differ substantially in their sequences, but that proteins L7 and L12 have considerable structure homology.
TL;DR: Incorporation of amino acid into protein was reduced in both brain and liver ribosomes 1.5–3 hours after a single administration of ethanol, suggesting ribosomal protein synthesis is rather insensitive to the in vitro addition ofanol, as compared with the in vivo administration.
TL;DR: A new drug, camptothecin, has been used to study the regulation of ribosome synthesis in HeLa cells and it is found that ribosomal proteins made in the presence of campthecin do not accumulate in the nucleolus, and are not subsequently used to form ribosomes if RNA synthesis is allowed to resume.
Abstract: A new drug, camptothecin, has been used to study the regulation of ribosome synthesis in HeLa cells. 5 μM camptothecin inhibits the synthesis of heterogeneously sedimenting nuclear RNA by about 70%. Camptothecin also blocks a specific step in the processing of ribosomal precursor RNA, allowing the conversion of 45S RNA to 32S RNA, but inhibiting the conversion of 32S RNA to 28S RNA. The action of camptothecin, unlike that of actinomycin D, is rapidly reversible. Within 5 min after the removal of the drug, ribosomal precursor RNA synthesis and maturation resume at the normal rate.
Ribosomal proteins made in the presence of camptothecin do not accumulate in the nucleolus, and are not subsequently used to form ribosomes if RNA synthesis is allowed to resume.
TL;DR: It is observed that 30 min after injection of glucagon and H, 32P0,, phosphorylation of ribosomal proteins was strongly increased, and autoradiography after electrophoresis of these proteins showed that phosphorylated of one ofThese proteins was stimulated 2 or 3 fold after injectionof glucagon.
TL;DR: Synthesis of ribosomal proteins takes place in the cytoplasm and is independent of nuclear synthesis of Ribosomal RNA.
Abstract: Synthesis of ribosomal proteins takes place in the cytoplasm and is independent of nuclear synthesis of ribosomal RNA.
TL;DR: The number of specific binding sites for proteins on 16 s and 23 s ribosomal RNA of Escherichia coli was investigated and one 30 s protein, namely S11, bound specifically to 23 s rRNA.
TL;DR: The molecular weight distribution of ribosomal proteins in subunits of rabbit reticulocyte ribosomes was studied by electrophoresis in polyacrylamide gels containing sodium dodecyl sulphate to determine their molecular weights.
TL;DR: The rate-limiting step in the recovery of S. typhimurium from thermal injury was in the maturation of the newly synthesized rRNA, which was found associated with the new rRNA in ribosomal particles.
Abstract: When cells of S. typhimurium were heated at 48 C for 30 min in phosphate buffer (pH 6.0), they became sensitive to Levine Eosin Methylene Blue Agar containing 2% NaCl (EMB-NaCl). The inoculation of injured cells into fresh growth medium supported the return of their normal tolerance to EMB-NaCl within 6 hr. The fractionation of ribosomal ribonucleic acid (rRNA) from unheated and heat-injured cells by polyacrylamide gel electrophoresis demonstrated that after injury the 16S RNA species was totally degraded and the 23S RNA was partially degraded. Sucrose gradient analysis demonstrated that after injury the 30S ribosomal subunit was totally destroyed and the sedimentation coefficient of the 50S particle was decreased to 47S. During the recovery of cells from thermal injury, four species of rRNA accumulated which were demonstrated to have the following sedimentation coefficients: 16, 17, 23, and 24S. Under identical recovery conditions, 22, 26, and 28S precursors of the 30S ribosomal subunit and 31 and 48S precursors of the 50S ribosomal subunit accumulated along with both the 30 and 50S mature particles. The addition of chloramphenicol to the recovery medium inhibited both the maturation of 17S RNA and the production of mature 30S ribosomal subunits, but permitted the accumulation of a single 22S precursor particle. Chloramphenicol did not affect either the maturation of 24S RNA or the mechanism of formation of 50S ribosomal subunits during recovery. Very little old ribosomal protein was associated with the new rRNA synthesized during recovery. New ribosomal proteins were synthesized during recovery and they were found associated with the new rRNA in ribosomal particles. The rate-limiting step in the recovery of S. typhimurium from thermal injury was in the maturation of the newly synthesized rRNA.
TL;DR: Each protein of the 50S ribosomal subunit from E. coli has been purified by a combination of differential solubility in ammonium sulfate, ion-exchange chromatography, and molecular-sieve chromatography and, according to chemical criteria, reasonably pure.
Abstract: Twenty-seven proteins of the 50S ribosomal subunit from E. coli have been purified by a combination of differential solubility in ammonium sulfate, ion-exchange chromatography, and molecular-sieve chromatography. The amino acid compositions, tryptic peptides and molecular weights of these proteins have been analyzed. Each protein is unique with respect to amino acid sequence and, according to chemical criteria, reasonably pure. The sum of the molecular weights of the twenty-seven proteins is 495000. This means that the 50S subunit could accommodate one copy of each protein.
TL;DR: Three proteins and about three histidine residues are protected from photo-oxidation by the presence of poly(U) and tRNA, and one of these proteins is PI, which has been shown by Van Duin & Kurland (1970) to stimulate poly( U) binding activity in 30 s subunits deficient in this protein.
TL;DR: Evidence is reported below which indicates, as expected, that ribosomes from two species differ in some of their protein components, but unexpectedly, some differences are also found in two different organs in the same species.