Fig. 4.

Minimal Sup35 fragments for the [VH] and [VK] strains. (A) Infectious [VH] fibers require Sup (1–53). Flow cytometry is used to normalize fiber length distribution of Sup (1–53)-GFP and Sup(1–47)Gly₆-GFP. Only Sup (1–53)-GFP fibers exhibit significant infectivity (54H/316: 54 [VH] of 316 randomly picked colonies). (B–D) Sup (1–40) transmits the [VK] structure faithfully. Sup (1–61)-GFP fibers of the [VK] strain type are wavy (B). Sup (1–40)-GFP fibers nucleated by [VK] exhibit jagged morphology (C), which reverts to the wavy shape when used as seeds to nucleate Sup (1–61)-GFP (D). (Scale bar, 100 nm.)