FIGURE 4.

Cysteines at positions 39, 57, 59, and 80 of Domain I are critical for NS5A dimerization. A, full-length NS5A-His with single mutations at each cysteine residue in Domain I were generated and used as prey in pulldown assays with GST or GST-Domain I NS5A as bait. These data are representative of three independent experiments using three different batches of recombinant NS5A proteins. B, cysteine mutants in A were tested for their ability to bind cyclophilin A with or without the presence of CsA (2 μm).