Autoprocessing of HSV-1 protease: effect of deletions on autoproteolysis.

HSV-1 protease is involved in virus maturation. It is autoproteolytic and processed from a larger precursor. We have analysed the autoproteolysis of UL26 ORF and shown by in vitro-coupled transcription and translation that the UL26 encoded protein is processed, leading to the accumulation of its N-terminal domain. The deletion of the residues 245-248 in UL26 ORF abolishes the N-terminal cleavage but not the C-terminal processing. Deletion of the 3' end of UL26 prevents production of the mature protease. These results strongly suggest that autoproteolysis is achieved in a defined order.