Com puter-Based Prediction and Experim ental Confirm ation of the jSR Membrane Protein of African Swine Fever Viru

The j5R open reading frame (ORF) of African swine fever virus was predicted by computing to encode a 12.9 kDa protein with two successive N terminal transmembrane domains and one C terminal antigenic epitope. Antibodies raised against a synthetic peptide derived from the C terminal epitope detected a specific protein of 23 or 25 kDa (depending on different isolates) in ASFV infected cells or purified extracellular ASFV virions. Immunofluorescence showed that the j5R protein was mainly located in the virus assembly sites within ASFV infected cells. Phase separation of purified extracellular ASFV virions and fractionation of ASFV infected cells demonstrated that the j5R protein was in the detergent phase and membrane fraction, confirming that the j5R protein was membrane associated.