title: Assignment of resonances of exchangeable protons in the NMR spectrum of the complex formed by Escherichia coli ribosomal protein L25 and uniformly nitrogen-15 enriched 5 S RNA fragment.
abstract: The downfield proton NMR spectrum of the aqueous nucleoprotein complex formed by Escherichia coli ribosomal protein L25 and uniformly nitrogen-15 enriched 5 S RNA fragment is presented. Many proton resonances show the effects of scalar coupling to nitrogen-15 and these resonances are assigned to nucleic acid imino protons. Selective nitrogen-15 decoupling difference proton spectroscopy revealed nitrogen-15 and proton chemical shift correlations from which the base types of nucleic acid imino proton resonances could be assigned because the nitrogen-15 chemical shifts of nucleic acid guanine and uracil imino nitrogens have separate small ranges for both nucleoproteins and isolated nucleic acids.
mesh_terms: D004926:Escherichia coli / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012335:RNA, Ribosomal / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*
chemical_list: D012335:RNA, Ribosomal; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; C031127:ribosomal protein L25