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Purpose of work The non-structural protein 4 (Nsp4) of porcine reproductive and respiratory syndrome virus (PRRSV) functions as a 3C-like proteinase (3CLpro) and plays a pivotal role in gene expression and replication. We have examined the biochemical properties of PRRSV 3CLpro and identified those amino acid residues involved in its catalytic activity as a prelude to developing anti-PRRSV strategies. The 3C-like proteinase (3CLpro) of porcine reproductive and respiratory syndrome virus (PRRSV) was expressed in Escherichia coli and characterized. The optimal temperature and pH for its proteolytic activity were 8C and 7.5, respectively. Na ? (1000 mM) and K ? (500 mM) were not inhibitory to its activity but Cu 2? , Zn 2? , PMSF and EDTA were significantly inhibitory. His 39 , Asp 64 and Ser 118 residues were identified to form the catalytic triad of PRRSV 3CLpro by a series of site-directed mutagenesis analysis. Keywords 3C-like proteinase A Nsp4 A Porcine reproductive and respiratory syndrome virus
Output:
Characterization of the biochemical properties and identification of amino acids forming the catalytic center of 3C-like proteinase of porcine reproductive and respiratory syndrome virus