Work

The rate of cleavage of GTP on the binding of Phe-tRNA.elongation factor Tu.GTP to poly(U)-programmed ribosomes of Escherichia coli.

Year: 1985

Type: article

Abstract: Interaction of Phe-tRNA.elongation factor Tu.GTP with poly(U)-programmed ribosomes containing an occupied P site can be described by a three-step kinetic mechanism. Initial binding is followed by the cleavage of GTP, and then a new peptide bond is formed. Rate constants controlling the first and third of these reactions are known, but only a lower limit for the rate constant of the cleavage step has been reported. We have determined this rate constant to be 20 s-1 at 5 degrees C, 30 s-1 at 15 degrees C, and 50 s-1 at 25 degrees C. This is much faster than the reverse step of the initial binding process and implies that the intrinsic accuracy of the ribosome in the initial selection step is sacrificed in favor of speed. The similarity of the kinetic and chemical mechanism of this GTP cleavage step with other nucleoside 5'-triphosphatases is discussed.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(17)36226-9

Authors: J F Eccleston, D B Dix, R C Thompson

Institutions: National Institute for Medical Research, University of Colorado Boulder

Language: English

Topic: RNA and protein synthesis mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Institute of General Medical Sciences