An unusual coordinated cleavage event in the processing of encephalomyocarditis virus polypeptides.

During the translation of encephalomyocarditis virus RNA in the rabbit reticulocyte lysate system, polypeptides 2B and 2C, encoded by the central region of the genome, appear simultaneously in the absence of any detectable 2BC precursor and at a time when translation has advanced into the region coding for polypeptide 3C. This implies the operation of closely coordinated proteolysis at two sites, with at least one cleaved by the virus-coded protease activity 3C.