individual rna species were not separately examined , the radiochromatographic data , however , which were obtained from digests of total rna preparations , present evidence that 6-thioguanosine 5'-diphosphate and 6-thioguanosine 5'-triphosphate exist as 5'-terminal starting nucleotides ( in trna and rrna ) and that 6-thioguanosine becomes incorporated into the highly modified dinucleoside triphosphate structures ( caps ) which commonly block the 5'-termini of eukaryotic poly ( a ) + mrna-molecules .
C0035668
rna
C0035701
rrna