FIG. 4.

Orthogonal views of the MNV-1 P-domain dimer. (a and b) Surface diagrams of the MNV-1 P-domain dimer. Individual monomers are surface colored in blue and green. The ribbon diagrams of the P1 domains are colored red, while the P2 domains are colored blue. (a) Side view of the dimer perpendicular to the 2-fold axis. (b) Top view looking down the 2-fold axis. A close-up of the ionic lock is shown in the inset. (c) Slice through the surface of the P-domain dimer interface showing the channel extending from one end of the dimer to the other along the 2-fold axis. (d) Slice through the surface view of the P domain, looking down into the channel (∼8 Å in diameter). This view is a 90° rotation from the orientation shown in panel c.