Showing papers on "Ribosomal protein published in 1973"
TL;DR: The results strongly suggest that 21 purified 30 S proteins together with 16 S RNA are sufficient to reconstitute 30 S subunits, and that no essential 30 S components were lost during the fractionation and purification of the30 S proteins.
246 citations
TL;DR: The distinctive clustering of hydrophobic and charged residues is quite remarkable and suggests that in situ certain of these regions may contain a binding site for components involved in peptide chain elongation.
Abstract: The primary structures of the ribosomal proteins A1 (= L7) and A2 (= L12) have been elucidated. Comparison of the two amino acid sequences confirms earlier studies by us (1972) which indicated that the two proteins are identical except that A1 possesses an N-terminal acetyl group.
Sequencing of tryptic and chymotryptic peptides was accomplished primarily by automatic solid-phase Edman degradation of 50- to 70-nanomole peptide samples. A large tryptic peptide T1Phe, which could not be sequenced by this method, was fragmented with elastase and its sequence mainly derived by conventional methods. The sequence of the first 51 residues of the nonacetylated A2-protein was obtained by Edman degradation in the Beckman sequencer.
A-protein comprises three distinct regions: I (residues 1—55), which is negatively-charged and hydrophobic, II (56—81), which is positively charged, and III (82—120), which is negatively charged and hydrophilic. α-Helix promoting residues are located primarily in regions I and III. ɛ-N-Monomethyllysine, which occurs in 50% of the A1 and A2 chains is located in the more flexible region II at position 81.
The distinctive clustering of hydrophobic and charged residues is quite remarkable and suggests that in situ certain of these regions may contain a binding site for components involved in peptide chain elongation.
196 citations
TL;DR: It has been shown that newly formed ribosomal RNA is found in native cytoplasmic subunits before passing to the polysomes in Saccharomyces cerevisiae.
179 citations
TL;DR: The miniature slab gel system described here is essentially identical to that reported by Kaltschmidt and Wittmann and has been employed to separate eukaryotic ribosomal proteins and to identify by radioautography those phosphorylated by protein kinase.
174 citations
TL;DR: Transduction experiments showed that the mutations affecting both proteins, L4 and L22, are located very close to the str and spc genes, nearer to the spc than to str gene.
Abstract: Ribosomes from nine E. coli mutants with high level resistance to the antibiotic erythromycin were isolated and their proteins were compared with those of the parental strains by two-dimensional polyacrylamide gel electrophoresis, by carboxymethylcellulose column chromatography and by immunological techniques. Two 50S proteins were found to be altered in the mutants: either L 4 or L 22.
160 citations
156 citations
TL;DR: The authors' studies show that in cytoplasmic extracts of infected cells, NS1 was actually associated with ribosomes, but not as a structural protein; it was simply adsorbed to both the large and the small ribosomal subunits by salt-dissociable bonds.
130 citations
TL;DR: Modification of 23 S RNA, presumably the previously observed methylation to form dimethyladenine, is responsible for the resistance to the antibiotics in this strain of S. aureus.
109 citations
TL;DR: A strong interaction between protein S12, which confers streptomycin dependence, and protein S4 or S5, which can suppress this dependence is suggested.
Abstract: Revertants from streptomycin dependence to independence were isolated as single step mutants from six different streptomycin dependent strains. The ribosomal proteins from 100 such mutants were analyzed by two-dimensional polyacrylamide gel electrophoresis and some of them were also examined by immunological techniques. Altered proteins were found in 40 mutants, 24 in protein S4 and 16 in protein S5. No change in any other protein was detected.
104 citations
TL;DR: The precursors p30 S and p 2 50 S can be converted into active 30 S and 50 S sub-units, respectively, by incubation at 42 °C in the presence of ribosomal proteins and under RNA methylating conditions.
102 citations
TL;DR: Most, if not all, of the E. coli 30S ribosomal proteins have functionally equivalent counterparts among B. proteins, suggesting that the fundamental structural organization of ribosomes may be the same throughout organisms.
Abstract: 30S ribosomal proteins from Bacillus stearothermophilus (B. proteins) have been fractionated and characterized with respect to their ability to replace various E. coli 30S proteins (E. proteins) in the E. coli 30S ribosome reconstitution system. The functional counterparts of all the E. proteins, except S1, S6, S9, and S13, have been tested. In all cases, B. proteins can substitute for E. proteins. Several purified B. proteins are chemically different from their functionally homologous E. proteins. Five B. proteins are immunochemically related to E. proteins; this set includes two proteins that could not be tested in the reconstitution system (S9 and S13). Thus most, if not all, of the E. proteins have functionally equivalent counterparts among B. proteins, even though properties of the two ribosomes are different in several respects. These results suggest that the fundamental structural organization of ribosomes may be the same throughout prokaryotic organisms.
TL;DR: The reaction with N-ethyl maleimide provides a criterion other than biological activity for characterizing different ribosomal forms and a tool for mapping the 30 S subunit for specific functional sites.
TL;DR: The data indicate that probably a single 30s ribosomal protein has been crosslinked to the 3′-ribosyl terminus of 16s RNA in intact 30s Ribosomes in a stable, specific covalent crosslink.
TL;DR: It was inferred that the presence of small amounts of these proteins on 50S subunits was compatible with their presence at the subunit interface, and the capacity of proteins S11 and S12 to bind to 23S RNA was demonstrated.
Abstract: The identification of ribosomal proteins that occur at, or near, the subunit interface of the 30S and 50S subunits in the E. coli 70S ribosome was attempted by studying the effect of antibodies on the Mg++ dependent dissociation-association equilibrium of 70S ribosomes. Dissociated ribosomes were mixed with monovalent fragments of IgG antibodies (Fab's) specific for each ribosomal protein and then reassociated into intact 70S particles. Various degrees of inhibition of this reassociation were observed for proteins S9, S11, S12, S14, S20, L1, L6, L14, L15, L19, L20, L23, L26 and L27. A small amount of aggregation of 50S subunits was caused by IgG's specific for the proteins S9, S11, S12, S14 and S20 and purified 50S subunits. It was inferred that the presence of small amounts of these proteins on 50S subunits was compatible with their presence at the subunit interface. Finally, the capacity of proteins S11 and S12 to bind to 23S RNA was demonstrated.
TL;DR: SDS two-dimensional gel electrophoresis revealed that the molecular weight of ribosomal proteins is conserved in all tested bacteria.
Abstract: The ribosomal proteins from several Bacillus species were compared by two-dimensional gel electrophoresis and immunological methods. The results revealed great heterogeneity among most Bacillus species. Comparison of ribosomal proteins from Bacilli with those of E. coli by two-dimensional gel electrophoresis showed little similarities, while structural homologies could be found by immunological methods. SDS two-dimensional gel electrophoresis revealed that the molecular weight of ribosomal proteins is conserved in all tested bacteria.
TL;DR: The amino acid sequence of protein S4 is determined and the molecular mechanism of both the mutations in S4 and the protein-RNA interaction has been studied in some detail.
TL;DR: This paper studied the evolution of ribosomal proteins over a spectrum of 13 species ranging from man to plants using a two-dimensional polyacrylamide gel electrophoresis technique.
Abstract: We have studied the evolution of ribosomal proteins over a spectrum of 13 species ranging from man to plants using a two-dimensional polyacrylamide gel electrophoresis technique. We tried to quantify the proximity of these species by coelectrophoresing the proteins from various combinations of two species. The following tentative conclusions have been reached.
1
For reptiles and birds which diverged 300 million years ago from the line leading to mammals, ribosomal proteins display the same fingerprints as mammals.
2
For amphibians and fish which diverged 350–400 and 440–500 million years ago respectively, the fingerprints show limited differences compared with mammals. Those of fish show some diversity within the species.
3
For lower species (crustaceans, molluscs) and plants, the fingerprints exhibit a great diversity.
TL;DR: Two cyclic adenosine 3':5'-monophosphate-activated protein kinases were isolated from rat liver cytosol and separated by DEAE-cellulose chromatography; protein kinase I was further purified by hydroxylapatite chromatography.
TL;DR: The results suggest that proteins L7 and L12 are part of the binding site for initiation factor IF-2, but that they are more intimately involved in the 5'-guanosine triphosphate hydrolysis catalyzed by the factor.
TL;DR: CsCI-prepared 50S cores in the presence of groups of individual split proteins were tested for their capacity to support EF-G dependent GTP hydrolysis and found that L7L12 and L10 cannot replace L6, or vice versa.
TL;DR: The range of fragments observed is sufficient to enable the data to be combined with Nomura's “assembly map” and data from protein crosslinking experiments, into a preliminary three-dimensional arrangement of the proteins.
Abstract: 1
30-S ribosomal subparticles from Escherichia coli were hydrolysed with ribonuclease T1, pancreatic ribonuclease or micrococcal nuclease in the presence of 2 M urea, and various concentrations of magnesium and ethanol. The RNA · protein fragments produced were separated on 5% polyacrylamide/agarose composite gels, and fractions from these gels were subjected to protein analysis on 17.5% periodate-soluble polyacrylamide gels run in the detergent sarkosyl, using the technique already published.
2
A wide range of RNA · protein fragments was obtained by this procedure, each containing a few specific ribosomal proteins. The strict criteria already published for determining the specificity of the proteins in each fragment were applied. The RNA · protein fragments divide into two distinct groups, those containing some or all of proteins S7, S9, S10, S13, S14 and S19, and those containing some or all of proteins S4, S5, S6, S8, S11, S15, S16(17), S18 and S20. Proteins S1, S2, S3, S12 and S21 were not found in specific fragments.
3
The individual proteins found together in specific RNA · protein fragments are interpreted as being close neighbours in the 30-S particle. The range of fragments observed is sufficient to enable the data to be combined with Nomura's “assembly map” and data from protein crosslinking experiments, into a preliminary three-dimensional arrangement of the proteins.
TL;DR: It is investigated whether this accessibility can be altered by the presence of bound mRNA or tRNA and described here some ribosomal proteins from the 30S subunit which have decreased susceptibility to tryptic digestion in these conditions.
Abstract: THE large number of physically and chemically distinct proteins that contribute to the structure of the Escherichia coli ribosome1–5 is in keeping with its many functions which often seem to be attributable to particular protein components of the 30S ribosomal subunit. A complete allocation of functions to specific proteins is vital to an understanding of the mechanism of action of the ribosome in terms of its constituent parts. Several groups6–9 have used tryptic digestion of ribosomal subunits to estimate the relative accessibility of the proteins. We have investigated whether this accessibility can be altered by the presence of bound mRNA or tRNA and describe here some ribosomal proteins from the 30S subunit which have decreased susceptibility to tryptic digestion in these conditions. The involvement of many of these proteins in mRNA and tRNA binding functions, suggested by previous experiments, leads us to propose the use of the technique in the identification of regions of the ribosome to which the various functional ligands are bound during protein synthesis.
TL;DR: The present data are consistent with the view that the interaction between ribosomes and EF-G that results in GTP hydrolysis occurs on, and is limited to, proteins L7 and L12 on the surface of the 50S ribosomal subunit.
Abstract: Rabbit antibodies produced against 50 of the 55 individually purified ribosomal proteins of Escherichia coli were tested for their ability to interfere with the formation of the ribosome·EF-G·GDP complex. Only antibodies produced against proteins L7 and L12 inhibited complex formation, and they did so completely. These two proteins were previously shown to be immunologically indistinguishable and necessary for the interaction between ribosomes and EF-G. The present data are consistent with the view that the interaction between ribosomes and EF-G that results in GTP hydrolysis occurs on, and is limited to, proteins L7 and L12 on the surface of the 50S ribosomal subunit.
TL;DR: The ribosomal proteins of seven different Enterobacteriaceae were compared with those of E. coli by two-dimensional gel electrophoresis and by immunological methods indicating that few, if any, of the ribosome proteins among the tested Enterobacteriaiaceae are identical.
Abstract: The ribosomal proteins of seven different Enterobacteriaceae were compared with those of E. coli by two-dimensional gel electrophoresis and by immunological methods. The ribosomal proteins of all Enterobacteriaceae were found to be very similar in molecular weight and in their electrophoretic properties. However, more dissimilarities could be detected by immunological methods thus indicating that few, if any, of the ribosomal proteins among the tested Enterobacteriaceae are identical. Ribosomes from all Enterobacteriaceae possess a protein which is electrophoretically identical with protein S7 from strain B (and not strain K) of E. coli.
TL;DR: Polyinosinic acid: polycytidylic acid (poly I: C) induced a rapid, short-lived immunity to all three Salmonella species, and ribosomal RNA failed to elicit any rapid nonspecific response to infection.
Abstract: Ribosomal proteins isolated from Salmonella typhimurium were effective in inducing immunity in mice. This immunity was specific since animals immunized with ribosomal proteins from S. typhimurium were not protected against challenge with S. cholerae-suis or S. enteritidis. Immunity was evident as early as 5 days after immunization. Ribosomal ribonucleic acid (RNA) failed to provide any effective immunity in mice. Polyinosinic acid: polycytidylic acid (poly I: C) induced a rapid, short-lived immunity to all three Salmonella species. In contrast, ribosomal RNA failed to elicit any rapid nonspecific response to infection.
TL;DR: Three protein kinase activities have been identified in ribosome-free supernatant from rabbit reticulocytes by DEAE-chromatography, and one of these kinases preferentially phosphorylate histone, and alsoosphorylate identical ribosomal proteins.
Abstract: Three protein kinase activities have been identified in ribosome-free supernatant from rabbit reticulocytes by DEAE-chromatography. Two of the protein kinase activities have similar substrate specificities, but differ in respect to dependency on cAMP for activation. These kinases preferentially phosphorylate histone, and also phosphorylate identical ribosomal proteins. One protein band in the 40S ribosomal subunit and six protein bands in the 60S subunit are phosphorylated, as demonstrated by Na dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The third kinase activity preferentially phosphorylates casein, instead of histone, and can use both [γ-32P]ATP and [γ-32P]GTP as phosphate donors. This protein kinase activity phosphorylates one protein band in the 40S subunit different from that phosphorylated by the other two kinases and four bands in the 60S subunit, only one of which is coincident with the proteins phosphorylated by the histone-specific activities.
TL;DR: Electrophoresis of the proteins of the 50S chloroplast ribosome subunit reveals that there are at least two detectable differences between Nicotiana tabacum and N. glauca.
TL;DR: The interpretation of the results of five different experimental approaches indicate that all 21 proteins of the 30S subunit have determinants available for antibody binding, including IgG's and their monovalent papain fragments.
Abstract: The accessibility of each of the proteins on the E. coli 30S ribosomal subunit was established by investigating whether or not immunoglobulins (IgG's) and their monovalent papain fragments (Fab's), specific for each of the 21 single ribosomal proteins, bind to the 30S subunit. The interpretation of the results of five different experimental approaches, namely Ouchterlony double diffusion and immunological “sandwich” methods, sucrose gradient and analytical ultracentrifugation, and functional inhibition tests, indicate that all 21 proteins of the 30S subunit have determinants available for antibody binding. There were quantitative differences between the degree of accessibility of the different ribosomal proteins. An attempt was made to correlate the results with the protein stoichiometric data of the small subunit proteins.