Tertiary structure in transfer ribonucleic acids.

Abstract

Transfer RNAs (sRNA) are key participants in the elaborate biological process that assures the assembly of uniquely sequenced polypeptide chains. They impart specificity to protein synthesis at two levels: the first involves the adaptation of the different amino acids to chemical forms complementary to the language of the genetic code, while the second involves the actual reading of the coded message. Both these functions of sRNA must obviously depend upon sensitive and highly specific interactions between sRNA molecules and certain enzymes. For the first function, specificity is achieved by bringing together different sRNAs with particular aminoacyl-sRNA synthetases. In the second function, which involves general peptide bond formation, fidelity is assured by a group of enzymes (and the ribosome) that apparently are not specific for individual sRNAs. Instead, these enzymes show specificity, presumably, for a particular stereochemical arrangement (with a common component from all sRNAs) that is possible only when the...