Cucumber mosaic virus RNA contains 7-methyl guanosine at the 5'-terminus of all four RNA species.

Purified cucumber mosaic virus (CMV) RNA was reacted with NaIO4 and then [3H]KBH4 to label ends containing exposed 2',3'-hydroxyls. The four major RNA species were then fractionated by polyacrylamide gel electrophoresis. Analysis of digests of these RNAs by ribonucleases T1 plus T2, alkaline phosphatease, snake venom diesterase and nucleotide pyrophosphatase by means of paper electrophoresis and ion-exchange chromatography indicated that the sequence m7G(5')ppp(5')N was present at the 5'-end of 75-92% of all RNA molecules. In addition, about 90% of the 3'-ends terminated in either adenosine or cytidine.