Conformational Studies ofEscherichia coli Ribosomes with the Use of Acridine Orange as a Probe
| Autor: | Kazuo Horie, Akira Wada, Hideo Fukutome |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Stereochemistry
Stacking Biochemistry Ribosome Phosphates chemistry.chemical_compound 5S ribosomal RNA Centrifugation Density Gradient Escherichia coli Magnesium Binding site Molecular Biology Dose-Response Relationship Drug Eukaryotic Large Ribosomal Subunit Spectrum Analysis Acridine orange General Medicine Ribosomal RNA Acridine Orange RNA Bacterial chemistry RNA Ribosomal Nucleic Acid Conformation Eukaryotic Ribosome Ribosomes |
| Zdroj: | The Journal of Biochemistry. 90:449-461 |
| ISSN: | 1756-2651 0021-924X |
| DOI: | 10.1093/oxfordjournals.jbchem.a133492 |
| Popis: | The interaction of E. coli vacant ribosomes with acridine orange (AO) was studied, to obtain conformational information about rRNAs in ribosomes. Acridine orange binds to an RNA in two different modes: cooperative outside binding with stacking of bound AO's and intercalation between nucleotide bases. Free 16S and 23S rRNAs have almost identical affinities to AO. At 1 mM Mg2+, AO can achieve stacking binding on about 40% of rRNA phosphate groups. The number of stacking binding sites falls to about 1/3 in the 30S subunit in comparison with free 16S rRNA. In the 50S subunit, the number of stacking binding sites is only 1/5 in comparison with free 23S rRNA. Mg2+ ions are more inhibitory for the binding of AO to ribosomes than to free rRNAs. The strength of stacking binding appears to be more markedly reduced by Mg2+ in active ribosomes than in rRNAs. "Tight couple" 70S particles are less accessible for stacking binding than free subunits. The 30S subunits that have irreversibly lost the capability for 70S formation under low Mg2+ conditions have an affinity to AO that is very different from that of active 30S but similar to that of free rRNA, though the number of stacking binding sites is little changed by the inactivation. 70S and 30S ribosomes with stacking bound AO's have normal sedimentation constants, but the 50S subunits reversibly form aggregates. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|