FIG. 1.

(A) Schematic representation of the Ebola virus GP. The GP is cleaved at position 501 into GP1 and GP2 subunits. The signal peptide, the fusion peptide, and the TM anchor are shown as shaded boxes, while the two helices are depicted as open boxes. The amino acid sequence between positions 554 and 630 is presented beneath the structure in single-letter code, and the residues in which mutations were introduced are indicated with italic letters. (B) Three-dimensional structure of the Ebola GP2 monomer. The residues containing a mutation are indicated by cyan coloring in the N-terminal helix and by violet in the C-terminal helix. (C) Helical wheel representation of the N- and C-terminal helices. N and C represent the N- and C-terminal helices, respectively. The a through g lettering represents the heptad repeats. Residues in which a mutation was introduced are indicated by boldface italic letters, with their respective positions given underneath the letters. (D) Expression of the wild-type Ebola virus GP and its mutants. 293T cells were transfected with a plasmid expressing Ebola virus GP or its mutants and lysed in a sample buffer. Proteins in the lysates were separated by SDS–10% PAGE, transferred to a PVDF membrane, and detected by anti-Ebola virus GP-SGP rabbit serum. Molecular masses of the marker proteins are shown on the left.