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The rate constants for eucaryotic initiation factor 3 (eIF3) association and dissociation with 40S ribosomal subunits and 80S monosomes have been determined. These rate constants were determined by laser light scattering with unmodified eIF3. The affinity of eIF3 for 40S subunits is about 30-fold greater than for 80S ribosomes. This difference in affinity resides mainly in the association rate constants. Rate constants of 8.8 X 10(7) and 7.3 X 10(6) M-1 s-1 were obtained for eIF3 binding to 40S subunits and 80S ribosomes, respectively. From thermodynamic cycles, the affinity of eIF3-40S subunits for 60S subunits is about 30-fold lower than free 40S subunits for 60S subunits. A calculation shows that under these conditions and assuming simple equilibria, approximately 12% of ribosomal subunits would associate via a reaction of 40S-eIF3 with 60S subunits as opposed to a path where eIF3 dissociates from the 40S subunits prior to association with 60S subunits.
D J Goss, and
D J Rounds
April 2005,
RNA (New York, N.Y.),
D J Goss, and
D J Rounds
November 1988,
Biochimica et biophysica acta,
D J Goss, and
D J Rounds
August 1974,
Proceedings of the National Academy of Sciences of the United States of America,
D J Goss, and
D J Rounds
May 1980,
Biochemistry,
D J Goss, and
D J Rounds
September 1995,
Biochemical and biophysical research communications,
D J Goss, and
D J Rounds
November 1980,
Biochimica et biophysica acta,
D J Goss, and
D J Rounds
October 1970,
Proceedings of the National Academy of Sciences of the United States of America,
D J Goss, and
D J Rounds
August 1982,
The Journal of biological chemistry,
D J Goss, and
D J Rounds
January 1987,
The Journal of biological chemistry,
D J Goss, and
D J Rounds
September 1967,
Proceedings of the National Academy of Sciences of the United States of America,
