Partial assignment of resonances in the /sup 19/F nuclear magnetic resonance spectra of 5-fluorouracil-substituted transfer RNAs

Journal Article · Tue Jan 12 04:00:00 EST 1988 · Biochemistry; (United States)

OSTI ID:5444485

Hardin, C C; Gollnick, P; Horowitz, J

Features of the /sup 19/F nuclear magnetic resonance (NMR) spectra of three purified 5-fluorouracil-(FUra-)substituted Escherichia coli tRNAs, tRNA/sub 1//sup Val/, tRNA/sub m/sup Met/, and tRNA/sub f/sup Met/, are compared. Each of the tRNA species can be resolved into two isoaccepting forms, A and B, whose /sup 19/F NMR spectra differ in the shift of one peak from the 4.5 to 4.8 parts per million (ppm) range (FUra = 0) in the spectrum of isoaccpetor B upfield to ca. -15 ppm in that of isoacceptor A. Because the sequences of the two isoacceptors of each tRNA differ only at one position in the D loop, that normally occupied by a dihydrouridine residue, the authors assign the 4.5 ppm peak in the spectrum of fluorine-labeled tRNA/sub 1//sup Val/ to FUra 17 and the resonance at 4.6 ppm in the spectrum of fluorouracil-substituted tRNA/sub m/sup Met/ to FUra20. A reciprocal /sup 19/F )/sup 18/F) nuclear Overhauser effect is observed between the downfield peaks A and B in the /sup 19/F NMR spectrum of /sup 19/F-labeled rRNA/sub 1//sup Val/. Assuming that fluorine-labeled tRNA/sub 1//sup Val/ has a structure similar to that of yeast tRNA/sup Phe/, only FUra54 and -55 are close enough (4-5 A) to give an appreciable /sup 18/F homonuclear Overhauser effect. Peaks A and B have therefore been assigned to FUra54 and -55. The lowest field resonance (peak A) in the /sup 19/F spectra of each of the three tRNAs exhibits a uniquely large chemical shift change with changing ionic strength or magnesium ion concentration. This similarity suggests that peak A corresponds to a conserved base in the tRNAs and is consistent with assignment of peak A in the /sup 19/F NMR spectra of all three fluorinated tRNAs to the 5-fluorouracil residue.

• Research Organization: Iowa State Univ., Ames
• OSTI ID: 5444485
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:1; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKALI METAL COMPOUNDS
AMINO ACIDS
ANTIMETABOLITES
AUTORADIOGRAPHY
AZINES
BACTERIA
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTROPHORESIS
ELEMENTARY PARTICLES
ESCHERICHIA COLI
EVEN-ODD NUCLEI
FERMIONS
FLUORINE 19
FLUORINE ISOTOPES
FLUOROURACILS
HADRONS
HALIDES
HALOGEN COMPOUNDS
HEAVY WATER
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAGNETIC RESONANCE
METHIONINE
MICROORGANISMS
MOLECULAR STRUCTURE
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUCLEIC ACIDS
NUCLEONS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OVERHAUSER EFFECT
OXYGEN COMPOUNDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PROTONS
PYRIMIDINES
RADIOISOTOPES
RESONANCE
RNA
SODIUM CHLORIDES
SODIUM COMPOUNDS
SPECTRA
STABLE ISOTOPES
TRANSFER RNA
URACILS
VALINE
WATER