A Covalently Linked Protein at the 5'-Ends of the Genomic RNAs of Pea Enation Mosaic Virus

Evidence is presented for the presence of a covalently linked protein that is attached to the 5'-ends of genomic RNA of pea enation mosaic virus (PEMV). Nuclease digestion of PEMV RNA released protein with an apparent mol. wt. of approx. 17500. The absence of a 5'-cap and the inability to introduce [³²P]phosphate into the 5'-termini of these RNAs suggests that the protein is covalently bound to PEMV RNA.