FIG. 5.

Full-length scrambled Ure2p variants form fibers with protease resistant cores. Full-length Ure2-21p, -22p, and -25p were purified under native conditions. Significant precipitate was observed after overnight rotation at 4°C. Precipitates were digested with 0.1 mg of proteinase K/ml at 37°C for 16 h, and the insoluble fraction was collected, washed, and stained with uranyl acetate. Electron micrographs compare undigested (left) and digested (right) filaments. Bar, 100 nm.