Effect of a 2-methylthio-N6-isopentenyladenosine deficiency on peptidyl-tRNA release in Escherichia coli.

We examined the effect of miaA, a mutation conferring a deficiency in 2-methylthio-N6-isopentenyladenosine in tRNA, on patterns of peptidyl-tRNA accumulation in Escherichia coli strains deficient in peptidyl-tRNA hydrolase activity. A specific reduction in peptidyl-tRNA accumulation was seen for tRNAs which normally contain the 2-methylthio-N6-isopentenyladenosine modification. These results provide new evidence in support of the ribosome editor model, which links peptidyl-tRNA release to mistranslation events.