Studies on the Formation of Transfer Ribonucleic Acid-Ribosome Complexes

The ability of altered transfer ribonucleic acid to compete with binding of [14C]aminoacyl- and [14C]tRNA was used as an estimate of its capacity to bind to ribosomes. Transfer ribonucleic acid with the terminal 3'-hydroxyl pA, pCpA, and pCpCpA enzymatically removed could bind to 70 S ribosomes with progressively lower efficiency; in contrast, binding to 30 S subunits was unimpaired. Transfer ribonucleic acid with the entire CCA terminus removed could bind to 70 S ribosomes about half as well as intact tRNA. Periodate oxidation reduced the binding of tRNA to 70 S ribosomes by 80%. Periodate, therefore, not only oxidizes the terminal vicinal hydroxyl groups of tRNA, but also 1 internal residue or more of certain tRNA species.