Fig. 2.

(A) Amino acid sequence alignment of the subtype 1a NS3/4A dominant quasispecies. (B) Amino acid sequence alignment of the subtype 1b NS3/4A dominant quasispecies. Amino acid changes are indicated relative to a consensus amino acid obtained from a reference database that included 307 sequences of subtype 1a or 328 sequences of subtype 1b (19). The catalytic triad of the NS3/4A protease formed by His 57, Asp 81, and Ser 139 is underlined. The Zn²⁺ binding site, Cys 97, Cys 99, Cys 145, and His 149, is also underlined. Dots indicate amino acid sequence identity.