Fig. 8.

Mutational analysis of the 3B+7 region of 3AB. (A) The amino acid sequence alignment analysis of 3AB proteins between EV71 and poliovirus. Regions of EV71 3AB: 3A, 1–86; 3B (VPg), 87–108(underlined); 3B+7, 82–108. Amino acids with an asterisk (*) were mutagenesis sites. (B and C) Electrophoresis analysis of expressed and purified eukaryotic proteins as illustrated in upper panel. Proteins were subjected to 10% SDS-PAGE, and protein bands were stained with Coomassie blue. (D and E) 3′-tailed RNA helix substrate (0.1 pmol) was reacted with proteins (10 pmol) as illustrated in upper panel, respectively, under standard reaction conditions. (F) The destabilizing activity was plotted as the percentage of the released RNA from the total RNA helix substrates (Y-axis) at indicated proteins as X-axis. Error bars represent standard deviation values from three separate experiments.