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Dynamics of tRNA: Experimental Neutron Spectra Compared with a Normal Mode Analysis
Author(s) -
Nardi F.,
Doster W.,
Tidor B.,
Karplus M.,
Cusack S.,
Smith J.C.
Publication year - 1994
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.199400026
Subject(s) - chemistry , normal mode , spectral line , globular protein , inelastic neutron scattering , inelastic scattering , molecular vibration , harmonic , neutron scattering , atomic physics , molecular physics , neutron , vibration , molecule , scattering , crystallography , nuclear physics , physics , optics , quantum mechanics , organic chemistry
A comparison is made of experimental inelastic neutron scattering spectra from tRNA with spectra calculated from a normal mode analysis of the molecule. The experimental data indicate that a dynamic transition occurs with temperature, as is seen in proteins. At low temperatures a broad peak is seen in the dynamic structure factor, due to the lowest frequency collective modes. This peak is centered at ˜40 cm −1 , somewhat higher in frequency than that observed in small globular proteins. The vibrational frequency distribution calculated from the normal mode analysis rises to a broad maximum at 50 cm −1 , in general accord with the experiment. However, the lowest frequency vibrations in the harmonic model (<40 cm −1 ) are not present in the experimental sample. Possible reasons for this are discussed.