Comparison of Ribonucleic Acid-Protein Interactions in Messenger Ribonucleoproteins, Ribosomes, MS2 Virus, and Qβ Virus Examined via Phosphorus-31 Nuclear Magnetic Resonance Relaxation

Philip H. Bolton, Gary Clawson, Vladimir J. Basus, Thomas L. James

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

The influence of the proteins in functional RNA-protein complexes on RNA has been investigated by using 31P NMR. The 31P spin-lattice relaxation time (T1), 31P{1H} nuclear Overhauser effect (NOE), off-resonance rotating frame spin-lattice relaxation time [formula omitted], and off-resonance intensity ratio (R) have been measured for polysomal messenger ribonucleoprotein particles and ribosomes isolated from rat liver, as well as the icosahedral bacteriophages MS2 virus and Qβ virus, and compared with those for free RNA. The results were dependent on the particular complex examined. In certain cases, the relation parameters were fitted to a motional model entailing two correlation times corresponding to a slow motion and a faster internal motion. The calculations include both dipole-dipole and chemical shift anisotropy contributions to relaxation. Analysis of the NMR relaxation data indicates that the internal motion of the RNA in intact ribosomes is restricted by a factor of about 5 relative to that of free RNA or limit-digest ribosomes. These results suggest that the “packaging” of RNA in the ribosome differs from that in either single- or double-stranded RNA and that the constraints of this packaging are removed by digesting 20–30% of the RNA in preparation of the limit-digest ribosome. Another variant is provided by the messenger ribonucleoprotein for which the T1 value suggested substantial coupling of the phosphorus nucleus to protein protons, unlike the other RNA-protein systems studied; the protein proton-RNA phosphorus interaction was confirmed by double-resonance experiments entailing observations of the phosphorus resonance during selective irradiation of the protein proton resonances. The 31P NMR results for MS2 virus and Qβ virus suggest that the RNA phosphodiester moiety in these viruses has an altered mobility (and perhaps structure) compared to that of free RNA. In addition, unlike the situation with pure RNA, the protons of water (or protons exchangeable with water) are dipolar coupled to the RNA phosphorus in the virus and ribosomes. The nature of the protein-RNA interaction clearly depends on the particular protein-RNA complex.

Original languageEnglish (US)
Pages (from-to)6073-6081
Number of pages9
JournalBiochemistry
Volume21
Issue number24
DOIs
StatePublished - 1982

All Science Journal Classification (ASJC) codes

  • Biochemistry

Fingerprint Dive into the research topics of 'Comparison of Ribonucleic Acid-Protein Interactions in Messenger Ribonucleoproteins, Ribosomes, MS2 Virus, and Qβ Virus Examined via Phosphorus-31 Nuclear Magnetic Resonance Relaxation'. Together they form a unique fingerprint.

Cite this