Abstract
Digestion of the N-acetylated-tyrosylated form of brome mosaic virus (BMV) RNA with proteinase K removed the 3'-blocking N-acetyl-tyrosine residue. Removal of the blocking group affected neither infectivity nor mRNA activity. The previously reported effect of acetylation of tyrosylated BMV RNA on infectivity appears to result from non-specific acetylation of the RNA.