A semi-symmetric vestige of an RNA apparatus with stereochemically controlled ribozyme capabilities is embedded and functions as the site peptide bond formation within all contemporary ribosomes, a finding that in line Lahav Leiserowitz earlier discoveries on chemical reactions. As structure this semi-symmetrical self-folded entity almost fully conserved known it seems to be resilient evolution...

The polyamine content of isolated E. coli ribosomes is dependent on the nature and concentration of the ions in the medium used for their preparation. When ribosomes are suspended in medium containing amines, the external amines are taken up by the ribosomes. When large amounts of amines are taken up by the ribosomes, part of the original ribosomal amines are displaced into the medium. Magnesiu...

Binding of [(35)S]thiostrepton to ribosomes from thiostrepton-sensitive and -resistant strains of Bacillus subtilis was studied. Ribosomes from thiostrepton-resistant strains bound relatively little thiostrepton compared with ribosomes from thiostrepton-sensitive B. subtilis. In addition, ribosomes from revertant strains that were obtained as thiostrepton-sensitive revertants from thiostrepton-...

Mitochondrial ribosomes comprise the most diverse group of ribosomes known. The mammalian mitochondrial ribosomes (55S) differ unexpectedly from bacterial (70S) and cytoplasmic ribosomes (80S), as well as other kinds of mitochondrial ribosomes. The bovine mitochondrial ribosome has been developed as a model system for the study of human mitochondrial ribosomes to address several questions relat...

Streptomycin-sensitive 70s ribosomes which are dissociated into SOS and 30s particles by dialysis against 1 X lop4 M magnesium acetate, and then reassociated in 0.02 M magnesium acetate, differ from nondissociated 70s ribosomes in r4C-aminoacyl soluble ribonucleic acid (sRNA) binding. 1. Reassociated ribosomes bind about twice as much 14C!phenylalanyl-sRNA in the presence of polyuridylic acid a...

Our previous finding that the tumor suppressor p53 is covalently linked to 5.8S rRNA suggested functional association of p53 polypeptide with ribosomes. p53 polypeptide is expressed at low basal levels in the cytoplasm of normal growing cells in the G1 phase of the cell cycle. We report here that cytoplasmic wild-type p53 polypeptide from both rat embryo fibroblasts and MCF7 cells and the A135V...

Membrane-bound ribosomes are thought to secrete protein for export and free ribosomes to secrete protein for intracellular use. The proportion of the total ribosomes that is bound to membranes in normal mouse kidneys has been estimated by three different methods, and the results have been compared with those obtained by a fourth method used by us previously. The most valid estimates appear to b...

Membrane-bound ribosomes are thought to secrete protein for export and free ribosomes to secrete protein for intracellular use . The proportion of the total ribosomes that is bound to membranes in normal mouse kidneys has been estimated by three different methods, and the results have been compared with those obtained by a fourth method used by us previously . The most valid estimates appear to...

The effect of the inclusion of EDTA and of heparin, in media used in the isolation of mitochondria, on the mitochindrial ribosome has been investigated. 1. Mitochondria isolated from Neurospora crassa in the presence of EDTA contain only a single type of monomeric ribosome, viz. 73 S. 2. Mitochondria isolated in the presence of Mg 2÷ contain both 79-S and 73-S monomeric ribosomes. The heterogen...