Further identification and characterization of products processed from the coronavirus avian infectious bronchitis virus (IBV) 1a polyprotein by the 3C-like proteinase.

Abstract

Proteolytic processing of the IBV 441-kDa 1a and 741-kDa la/1b fusion polyproteins to smaller mature products is mediated by two viral proteinases, namely, the papain-like Proteinase and the 3C-like proteinase (Fig. 1). The SC-like proteinase was identified as a 33-kDa protein in IBV-infected Vero cells (Lim et al., 2000). Characterization of the proteinase activities has shown that it cleaves the bulk of the polyproteins at conserved Q-S (G and N) dipeptide bonds, resulting in the release of more than ten mature products (Liu et al., 1994, 1997, 1998; Ng and Liu, 1998, 2000). It was shown to be associated with the membrane fraction in virus-infected cells by both cellular and biochemical studies (Ng and Liu, 2000).KeywordsVero CellInfectious Bronchitis VirusHuman Coronavirus 229EVesicular StainingRegion Specific AntiserumThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.