Fig. 1.

Reovirus particles and μ1 protein. (Left) Electron cryomicroscopy reconstructions of virions and ISVPs (3) and a diagram of ISVP*s. White, σ3; blue, μ1; green, λ2; orange, σ1; stars, released μ1N; triangles, released φ. (Right) Diagram of μ1 status in each particle type. Species inside the box are associated with particles; those outside the box are released. At least 50% of the μ1 copies in virions and ISVPs consist of full-length μ1 and μ1δ, respectively (containing uncleaved μ1), although the exact amount of cleavage is unknown (18, 19). Because standard disruption conditions for SDS/PAGE lead to μ1N cleavage (18), the main μ1 species seen in gels of ISVPs in this study is δ. μ1δ and μ1C (resulting from cleavage of μ1N only) are seen as minor species.