Is translation inhibited by noncognate ternary complexes?

Abstract

We studied the influence of an error-prone isoacceptor (tRNALeu4), as well as an intermediate (tRNALeu2) and a weak (tRNAVal) competitor of tRNAPhe on the poly(Phe) synthesis rate. Even at very high excess concentrations of these noncognate ternary complexes there was no significant effect on the translation rate. Our result argues against the assertion that in vivo translation is slowed down by noncognate tRNA and favours the hypothesis that the incorrect ternary complex concentrations are too low to saturate the ribosomes in vivo.