Identification and characterization of the porcine reproductive and respiratory virus ORFs 7, 5 and 4 products

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) causes abortions and respiratory diseases in pigs. The PRRSV genome is a positive- sense polyadenylated RNA molecule of about 15 kb. Along with the genes for structural proteins (envelope, matrix and nucleocapsid proteins) PRRSV genome contains a number of ORFs potentially encoding nonstructural proteins (ns). To investigate the nature of the PRRSV ORFs 7, 5 and 4 products, we have cloned the envelope (ORF5) nucleocapsid (ORF7) and ns4 (ORF4) protein genes in the bacterial expression vector pMAL(TM)-c2 under control of the 'tac' promoter and expressed the proteins in E. coli. The recombinant proteins were recognized by porcine and rabbit hyperimmune serums to PRRSV, suggesting their structural nature.