Biomaterial Database

Binding interactions between radiolabeled Escherichia coli elongation factor G and the ribosome. 1976

L Lin, and J W Bodley

We have prepared homogeneous radiolabeled Escherichia coli Elongation Factor G (EF-G) and examined its interactions with the ribosome. In agreement with earlier indirect observations we found that in the presence of high concentrations of fusidic acid approximately equimolar amounts of [3H]EF-G and [alpha-32P]GDP are stably bound to the ribosome. In the absence of fusidic acid, we observed a previously undescribed nucleotide-independent binding interaction between EF-G and the ribosome. This binding is detectable by rapid elution on small gel columns but is not apparent when reactions are analyzed by sucrose density gradient sedimentation. With the exception of the fact that the nucleotide-independent binding of EF-G to ribosome is apparently unaffected even by high concentrations of fusidic acid, it shares many properties in common with that binding which occurs in the presence of GDP. Nucleotide-independent binding requires magnesium ion (10 to 20 mM ) and does not require a monovalent cation but is strongly inhibited by even moderate concentrations of NH4Cl. This binding requires the presence on the ribosome of Protein L7/L12 and is inhibited by the antibiotic thiostrepton. Although we were unable to examine the binary ribosome.EF-G complex by equilibrium means, the observed stoichiometry under the conditions we employed did not exceed 0.2 mol of EF-G/mole of ribosome. Nonequilibrium measurements revealed that one-half of the EF-G was bound at a ribosome concentration of about 50 muM.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D010441	Peptide Chain Elongation, Translational	A process of GENETIC TRANSLATION, when an amino acid is transferred from its cognate TRANSFER RNA to the lengthening chain of PEPTIDES.	Chain Elongation, Peptide, Translational,Protein Biosynthesis Elongation,Protein Chain Elongation, Translational,Protein Translation Elongation,Translation Elongation, Genetic,Translation Elongation, Protein,Translational Elongation, Protein,Translational Peptide Chain Elongation,Biosynthesis Elongation, Protein,Elongation, Genetic Translation,Elongation, Protein Biosynthesis,Elongation, Protein Translation,Elongation, Protein Translational,Genetic Translation Elongation,Protein Translational Elongation
D010445	Peptide Elongation Factors	Protein factors uniquely required during the elongation phase of protein synthesis.	Elongation Factor,Elongation Factors, Peptide,Factor, Elongation,Factors, Peptide Elongation
D010761	Phosphorus Radioisotopes	Unstable isotopes of phosphorus that decay or disintegrate emitting radiation. P atoms with atomic weights 28-34 except 31 are radioactive phosphorus isotopes.	Radioisotopes, Phosphorus
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002850	Chromatography, Gel	Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.	Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005672	Fusidic Acid	An antibiotic isolated from the fermentation broth of Fusidium coccineum. (From Merck Index, 11th ed). It acts by inhibiting translocation during protein synthesis.	Fucithalmic,Fusidate Sodium,Fusidic Acid, Sodium Salt,Fusidin,Silver Fusidate,Sodium Fusidate,Stanicide,Acid, Fusidic,Fusidate, Silver,Fusidate, Sodium,Sodium, Fusidate
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012270	Ribosomes	Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.	Ribosome