Open AccessInteraction of tRNA with the A and P sites of rabbit‐liver 80S ribosomes and their 40S subunits
Author(s) -
RODNINA Marina V.,
EL'SKAYA Anna V.,
SEMENKOV Yuri P.,
KIRILLOV Stanislav V.
Publication year - 1989
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1989.tb15150.x
Subject(s) - ribosome , transfer rna , cooperativity , p site , eukaryotic ribosome , cooperative binding , eukaryotic small ribosomal subunit , biochemistry , binding site , a site , biology , chemistry , protein subunit , crystallography , biophysics , rna , gene
The interaction between tRNA and rabbit liver 80S ribosomes and 40S subunits was studied using a nitrocellulose membrane filtration technique. Binding of the different tRNA forms (aminoacyl‐, peptidyl‐ or deacylated) to poly(U)‐programmed 40S subunits and 80S ribosomes was found to be a cooperative process. The association constants of AcPhe‐tRNA Phe for the A and P sites of 80S ribosomes and the cooperativity constant were measured at different temperature and Mg 2+ concentration. The AcPhe‐tRNA Phe association constant for the P site was shown to be between 2 × 10 7 M −1 and 2 × 10 8 M −1 at 25–37°C and 5–20 mM Mg 2+ , while the affinity for the A site was 10–100‐fold lower. The cooperativity constant was shown to decrease with the increase of incubation temperature and the decrease of Mg 2+ concentration. The affinity of AcPhe‐tRNA Phe for the A site of 80S ribosomes was shown to depend upon the codon specificity of tRNA at the P site. The cooperativity of the tRNA interaction with 80S ribosomes was suggested to be mostly contributed by the association with the 40S subunit and result from the correct codon‐anticodon pairing at the P site. The data presented imply a codon‐anticodon interaction at the P site of eukaryotic 80S ribosomes.