Fig. 6. dsRNA binding of the Wenzhou1 coat protein.

(A) Overview of the protein-RNA interaction. A Wenzhou1 CP dimer is colored yellow-orange and purple as per each monomer and shown bound to a 10–base pair dsRNA fragment colored in teal and pale green as per each strand. An icosahedrally averaged F_o-F_c omit map contoured at 3 σ is presented to illustrate the observed RNA density inside the particle. (B) Detailed view of the protein-RNA interface. The side chains involved in RNA binding are shown in stick representation. (C) Discrimination of dsRNA binding between CP AB and CC dimers. The EF loop (yellow) of a neighboring CP CC dimer around an icosahedral threefold symmetry axis allows unrestricted binding of the RNA helix (top), while the same loop at the fivefold symmetry axis appears to cause a steric clash that prevents RNA binding (bottom).