To determine the region of 16S ribonucleic acid (RNA) at the interface between 30 and 50S ribosomes of Escherichia coli, 30 and 70S ribosomes were treated with T1 ribonuclease (RNase). The accessibility of 16S RNA in the 5' half of the molecule is the same in 30 and 70S ribosomes. The interaction with 50S ribosomes decreases the sensitivity to T1 RNase of an area in the middle of 16S RNA. A lar...

Ribosomes from muscle of diabetic rats synthesized less polyphenylalanine than normal ribosomes at low magnesium concentrations (5 to 10 mM), but they were more active than normal ribosomes at high magnesium concentrations (12.5 to 20 mM). The magnesium dependence of binding of phenylalanyl transfer RNA to normal and diabetic ribosomes closely paralleled the synthesis of polyphenylalanine. A po...

Synthetic biology constructs often rely upon the introduction of “circuit” genes into host cells, in order to express novel proteins and thus endow with a desired behavior. The expression these new “consumes” existing resources cell, such as ATP, RNA polymerase, amino acids, ribosomes. Ribosomal competition among strands mRNA may be described by system nonlinear ODEs called Flow Model (RFM). fo...

Abstract By interacting with the mRNA 5′ cap, translation initiation factor eIF4E plays a critical role in selecting mRNAs for protein synthesis eukaryotic cells. Caf20 is member of family proteins found across eukaryotes termed 4E-BPs, which compete eIF4G interaction eIF4E. independently interacts ribosomes. Thus, modulates selection process via poorly understood mechanisms. Here we performed ...

We have determined the number of proteins in rat skeletal muscle 80 S ribosomes and ribosomal subparticles by twodimensional polyacrylamide gel electrophoresis. The proteins were compared with those from liver ribosomes. The small subunit of muscle ribosomes contained 31 proteins: it had two proteins (SJ and S,,,2) which were not found in liver 40 S particles; one protein (S31*) was always foun...

Isolation of biologically active cell components from multicellular eukaryotic organisms often poses difficult challenges such as low yields and inability to retain the integrity and functionality of the purified compound. We previously identified a cap-independent translation enhancer (3'CITE) in the 3'UTR of Turnip crinkle virus (TCV) that structurally mimics a tRNA and binds to yeast 80S rib...

Subcellular localization of ribosomes defines the location and capacity for protein synthesis. Methods for in vivo visualizing ribosomes in multicellular organisms are desirable in mechanistic investigations of the cell biology of ribosome dynamics. Here, we developed an approach using split GFP for tissue-specific visualization of ribosomes in Caenorhabditis elegans. Labeled ribosomes are dete...

Ribosomes that stall before completing peptide synthesis must be recycled and returned to the cytoplasmic pool. The protein Dom34 and cofactors Hbs1 and Rli1 can dissociate stalled ribosomes in vitro, but the identity of targets in the cell is unknown. Here, we extend ribosome profiling methodology to reveal a high-resolution molecular characterization of Dom34 function in vivo. Dom34 removes s...

In a medium of high ionic strength, rat liver rough microsomes can be nondestructively disassembled into ribosomes and stripped membranes if nascent polypeptides are discharged from the bound ribosomes by reaction with puromycin. At 750 mM KCl, 5 mM MgCl(2), 50 mM Tris.HCl, pH 7 5, up to 85% of all bound ribosomes are released from the membranes after incubation at room temperature with 1 mM pu...

We have determined the equilibrium constants for the binding of AEDANS-labelled S1 to S1-depleted 30S and 70S ribosomes. For "tight" ribosomes, the association of S1 increases with the sixth power of Mg2+ concentration, but for 30S subunits and "loose" ribosomes, there is virtually no dependence of the association on Mg2+ over the same concentration range, 2-10 mM in Mg2+. The binding of S1 to ...