Artificial cleavage site recognized by plum pox potyvirus protease in Escherichia coli

A synthetic plum pox virus (PPV) NIb-CP cleavage site was recognized by a PPV protease in an in vivo Escherichia coli expression system. The presence of the natural NIb-CP cleavage site did not affect processing at the artificial one. However, although both the proteases and the cleavage sites of PPV and tobacco etch virus show high sequence homology, a similar cassette from the tobacco etch virus NIb-CP junction was not efficiently recognized by the PPV protease.