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Biophysical study of a molecular intermediate preceding collapse of tight couple and Kaltschmidt–Wittmann ribosomes
Author(s) -
Bonincontro Adalberto,
Nierhaus Knud H.,
Ortore Maria Grazia,
Risuleo Gianfranco
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03098-3
Subject(s) - ribosome , ribosomal rna , chemical physics , biophysics , population , particle (ecology) , spectroscopy , chemistry , biology , physics , ecology , biochemistry , quantum mechanics , rna , demography , sociology , gene
In previous works we evidenced, by different biophysical approaches, two levels of structural organization in Escherichia coli ribosomal particles. Thermal treatment up to a defined and non‐denaturing temperature causes demolition of only one level of structural complexity. By consequence the ribosomal particle exists in an intermediate state between the native form and the completely collapsed one. In this communication we report on a structural comparison of this intermediate state in Kaltschmidt–Wittmann (LC) and ‘tight couple’ (TC) ribosomes. Three different biophysical approaches were adopted: dielectric spectroscopy, fluorescence and light scattering. Differential responses to thermal treatment are evidenced in the two ribosomal species. In particular TC show a more compact structure and the overall particle population is more homogeneous than LC in the native state. On the other hand, LC particles after thermal treatment undergo major alterations of geometry and/or phenomena of supra‐particle aggregation.