Fig. 3.
Visualization of ORF6 by negative staining. A) ORF6 monomers. Preparation of ORF6 for EM under conditions that does not promote filamentation yields fields of small protein particles of relatively uniform size. Prepared by negative staining using 2% uranyl acetate. Insets show selected particles at higher magnification. Bar equals 100 nm (A) and 10 nm (B, C, D, E). F) ORF6 filamentation. ORF6 protein(16 pmol) was incubated overnight at 23° C in the presence of 20 mM Tris pH 7.4, 50 mM NaCl and 1 mM DTT (Materials and Methods). The samples were prepared for EM by staining with 2% uranyl acetate. Although most of the protein formed linear filaments, on some occasions the free ends fused to form circles (inset). Bar equals 300 nm in F.
