Solution of the ribosome riddle: how the ribosome selects the correct aminoacyl‐tRNA out of 41 similar contestants

Abstract

Three tRNA binding sites, the A, P and E sites, have been demonstrated on ribosomes of bacterial, archaebacterial and eukaryotic origin. In all these cases the first and the third site, the A and the E site, are allosterically coupled in the sense of a negative co‐operativity. Therefore, the allosteric three‐site model seems to be a generally valid description of the ribosomal elongation phase, where in a cycle of reactions the nascent peptide chain is prolonged by one amino acid. The molecular concept of the allosteric three‐site model explains the astonishing ability of the ribosome to select the correct substrate out of a large number of very similar substrates, and it provides a framework within which the mechanisms of the elongation factors could be understood. Molecular recognition: the special case of the ribosomal selection of the correct aminoacyl‐tRNA