FIG. 1.

Expression of SARS-CoV nonstructural proteins with a C-terminal HA-bio tag. (A) Sequences encoding individual nsp's were cloned into a modified pCAGGS vector that generates transcripts containing the posttranscriptional regulatory element from the Woodchuck hepatitis virus (WPRE). All constructs fuse a C-terminal HA-bio tag to each protein. TEV, tobacco etch virus. (B) Western blotting analysis (with mouse anti-HA [1:1,000; Covance]) to monitor the expression of nsp's. The expected sizes for nsp's with the C-terminal HA-bio tag are listed below the blot. Samples for nsp2, nsp5, nsp7, and nsp10 were diluted 10× prior to loading.