EXPRESSION IN ESCHERICHIA-COLI AND PURIFICATION OF THE ACTIVE AUTOPROTEASE P20 OF CLASSICAL SWINE FEVER VIRUS

The genes for Flaviviridae structural proteins are located at the 5' t erminus of the genome, while the 3' terminus contains the genes for th e non-structural proteins. The first protein product of the large ORF of pestiviruses, the p20 protein! is however a non-structural protein which possess an autoproteolytic activity. Here we report the cloning of the p20/p14 genes behind the strong Trc promotor and expression of the p20 at high levels in E. coli. The autoprotease p20 was responsibl e for its own release from the nascent polyprotein in E. coil and was further purified by chromatography techniques.