JAPANESE ENCEPHALITIS-VIRUS NONSTRUCTURAL PROTEIN NS3 HAS RNA-BINDINGAND ATPASE ACTIVITIES

Sequence data suggest that Japanese encephalitis virus (JEV) protein N S3 is a multifunctional protein with sequence motifs characteristic of a protease and a helicase. To examine the functions of JEV-NS3, a fus ion protein of NS3 in Escherichia coli was generated. Analysis by West ern blot using monospecific rabbit antisera generated against the fusi on protein (anti-MBJEN3) showed that NS3 was localized in the membrane fraction of JEV-infected cells and the particulate fraction of bacter ia extracts, The addition of anti-MBJEN3 sera reduced JEV-specific RNA synthesis activity in a in vitro system, In addition, NS3 was shown t o exhibit RNA binding and ATPase activities, suggesting this protein h as an important role in viral RNA replication in virus-infected cells.