Abstract
A cDNA containing almost all of the hepatitis A virus (HAV) P3 sequences was expressed as a fusion protein with Protein A. A novel poly(U) polymerase activity was detected in the periplasmic space of Escherichia coli cells transformed with this plasmid, and this activity showed many of the expected properties of a picornavirus 3Dpol. A number of HAV-specific polypeptides were detected in these cells, and it is unclear which of these was responsible for the polymerase activity.