FIGURE 4.

RNA binding is a prerequisite for the oligomeric transformation of refolded RNA-free SBV N. (A) Electrostatic potential surface map of the trimeric RNA-free SBV N. The potential RNA-binding clefts are on the outside of the trimer and available for RNA interaction. The dark arrows indicate the RNA-binding clefts. (B) Overall conformational changes of the SBV N before and after RNA binding. The refolded RNA-free SBV N is shown in yellow, the refolded SBV N–RNA complex is in cyan, and the RNA is shown in orange. (C) RNA-binding residues at the cleft undergo conformational changes for RNA binding. The residues prior to RNA binding are shown in yellow, and after RNA binding are shown in cyan.