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INTRAMOLECULAR ENERGY TRANSFER IN NATIVE tRNA AT ROOM TEMPERATURE
Author(s) -
Ballini JeanPierre,
Vigny Paul,
Thomas Gilles,
Favre Alain
Publication year - 1976
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1976.tb06832.x
Subject(s) - intramolecular force , transfer rna , chemistry , excitation , singlet state , absorption spectroscopy , energy transfer , luminescence , residue (chemistry) , aqueous solution , photochemistry , spectral line , absorption (acoustics) , wavelength , chemical physics , stereochemistry , atomic physics , materials science , rna , optics , physics , optoelectronics , organic chemistry , quantum mechanics , biochemistry , gene , excited state
— The odd nucleoside 4‐thiouridine, which is present in position 8 of 70% of E. coli tRNAs, possesses unusual spectroscopic properties which make it suitable for intramolecular energy transfer studies. Both its luminescence excitation spectrum and the action spectrum (230–380 nm) for the 8–13 link formation have been established in native E. coli tRNA at room temperature. The spectra are identical and present a new unexpected peak around 260 nm. At this wavelength, they are amplified by a factor of nine as compared with the absorption and excitation spectra of the free nucleoside in aqueous solution. The origin of this new peak is discussed and it is concluded that energy transfer does occur from the common nucleosides to the 4‐thiouridine residue. Using the values of the nucleosides to 4‐thiouridine distances inferred from the sets of atomic coordinates obtained on yeast tRNA phe crystals, a satisfactory account of our finding can be obtained assuming singlet‐singlet energy transfer. The efficiency of the mechanism is probably favoured by a good overlap between the emission spectra of the common nucleosides and the absorption spectrum of 4‐thiouridine.