IDENTIFICATION AND CHARACTERIZATION OF A 3C-LIKE PROTEASE FROM RABBITHEMORRHAGIC-DISEASE VIRUS, A CALICIVIRUS

Expression studies conducted in vitro and in Escherichia coli led to t he identification of a protease from rabbit hemorrhagic disease virus (RHDV). The gene coding for this protease was found to be located in t he central part of the genome preceding the putative RNA polymerase ge ne. It was demonstrated that the protease specifically cuts RHDV polyp rotein substrates both in cis and in trans. Site directed mutagenesis experiments revealed that the RHDV protease closely resembles the 3C p roteases of picornaviruses with respect to the amino acids directly in volved in the catalytic activity as well as to the role played by hist idine as part of the substrate binding pocket.