FIG. 4.

Putative NLS sequences. (A) Deduced primary amino acid sequence of the avian reovirus S1133 sigmaA protein. Putative monopartite NLSs are underlined and basic residues within these sequences are depicted in boldface type. (B) Crystal structure of the sigmaA region containing arginine residues R389 and R390. Note that surface exposure of these residues is prevented by an alpha-helix and that these residues form salt bridges with the aspartic acid residues at positions 377 and 378. (C) Crystal structure of a sigmaA monomer. The location of the arginine residues at positions 155 and 273 is indicated.