Biopolymers and cell. 1985. Volume 1. № 6. 318 - 322

D. B. Dorokhov, V. S. Shwarts, Yu. P. Semenkov

INTERACTION OF tRNA^phe-C-C-A(3'NH)-Phe WITH SMALL SUBUNIT OF ESCHERICHIA COLl

Summary

    The thermodynamic parameters of binding of tRNAphe-C-C-A(3'NH)Phe (a stable analogue of aminoacyl-tRNA) to SOS ribosomal subunit are studied. In the presence of template 30S subunit binds 2 molecules of tRNAphe-C-C-A(3'NH)-Phe to the acceptor (A) and peptidyl (P) sites. The affinity constants of the stable analogue of aminoacyl-tRNA for tRNA-binding sites of the small ribosomal subunit are measured: Kap=(3.5± ±0.35). 108 M-' and KaA~3-107 M~!. The results obtained indicate the great similarity in binding characteristics between Phe-tRNAphe and tRNAphe-C—C—A(3'NH)-Phe. It per¬mits applying tRNAphe-C-C-A(3'NH)-Phe as a very convenient model to study interaction between aminoacyl-tRNA and SOS subunit.