Translocation makes the ribosome less compact.
Translating ribosomes of Escherichia coli were prepared either in the pre-translocation or in the post-translocation states by a special technique based on the use of poly(U)-Sepharose columns where the template was coupled to the matrix through splittable -S-S- bridges. Elongation factors were absent from the final preparations. A neutron scattering study of the translating ribosomes in the two functional states was performed at different contrasts (various 1H2O/2H2O mixtures). Under conditions of a high contrast for the protein constituent the radius of gyration of the post-translocation-state ribosomes was found to be slightly greater than that of the pre-translocation-state ribosomes. Using the results of this study the conclusion can be drawn that translocation is accompanied by a spatial displacement of some parts of the ribosome with a magnitude of several ångström units.
Spirin
A S
AS
Baranov
V I
VI
Polubesov
G S
GS
Serdyuk
I N
IN
May
R P
RP
D004926:Escherichia coli / Q000235:genetics; D007700:Kinetics; D009502:Neutrons; D014176:Protein Biosynthesis; D012270:Ribosomes; D012542:Scattering, Radiation; D014178:Translocation, Genetic; D014965:X-Rays