Recognition of E coli tRNAArg by arginyl tRNA synthetase.

Escherichia coli tRNAArg was digested with ribonuclease T1 under restrictive conditions in order to dissect a minimum number of diester bonds. The number of diester bonds cleaved and their locations were determined by phosphorylation of the newly formed 5' hydroxyl groups with [32P] ATP and polynucleotide kinase. There was complete loss of aminoacylation of tRNAARg when two diester bonds were cleaved at the anticodon. However, this material retained the specific properties of synthetase recognition. Two fragments were derived by further digestion of this tRNA. One 19 nucleotide-long fragment derived from the 3' end of tRNAArg and another 18 nucleotide-long fragment derived from the 5' end of the molecule were required to maintain the properties of the specific recognition by the arginyl tRNA synthetase in the absence of the rest of the structure including the anticodon.