Leader polypeptides encoded in the 5′-region of the encephalomyocarditis virus genome

The authors have attempted to show here that: the initiator amino acid sequences, as defined by the presence of formyl-methionyl residue, are contained in a precursor polypeptide, preA; upon a short treatment of preA with a preparation of EMC virus-specific protease, these initiator sequences are cleaved off and emerge in two low-M sub(r) closely-related polypeptides, p14 and p12; after the removal of p14 (p12), the remaining moiety of preA corresponds to the precursor of capsid proteins, polypeptide A; preA, p14 and p12 appear to share an N-terminal amino acid sequence. These data suggest that all 3 latter polypeptides are initiated at a common single site on the viral genome and that p14 (p12) should occupy the N-terminal position on the EMC virus polyprotein cleavage map followed by polypeptide A, a precursor of the capsid proteins.