FIG 9.

MNV-1 P domain mutant viruses may escape MAb A6.2 neutralization by stabilization of the B conformation. (A) The location of the L386F mutation in the MNV-1 P domain. In the B conformation (blue), L386 lies between the two antigenic loops and does not contact the antibody. (B) As shown in this surface rendering of the top of the P domain, L386 (mauve) is fully exposed in the A conformation (tan). This suggests that L366F mutation will stabilize B over A and block antibody binding since the A conformation appears to be preferred for antibody binding. (C) Similarly, the A382R mutation may destabilize the A conformation since it would place an Arg residue in the middle of a highly basic patch of the P domain.