FIG 1.

Prokaryotic expression and purification of N-terminally truncated SARS-CoV-2 NCP. (A) Schematic representation of the fusion protein His₆–GST–3C–SARS-CoV-2 NCPΔ246 (calculated molecular weight, 47.3 kDa). (B) Total lysates preinduction (pre) and postinduction (post) and soluble (supernatant [SN]) and insoluble (pellet [P]) lysate fractions. (C) Eluate (E) and matrix (M) after on-column cleavage. (D) Amino acid sequence comparison of truncated CoV NCPs. Above the diagonal/light gray shading are identity scores (percent), and below the diagonal/dark gray shading are similarity scores (percent). MERS, Middle East respiratory syndrome.