Figure 1.

Plasmid construct and fusion protein. (A) Plasmid NA125 construct for expression of LF254-gp120 fusion protein in E. coli. GST, 26-kDa glutathione S-transferase domain from the parent vector pGEX-KG; LF^1–254, coding sequences for residues 1–254 of mature LF; gp120, coding sequences for residues 1–511 of HXB2-env gene. (B) Expressed GST-LF254-gp120 protein. The carboxyl-terminal residue of the linker from pGEX-KG was changed from D to E, and four residues, TRLQ, were added between the LF254 and gp120 portions of the construct due to DNA manipulations. The V3 epitope, RGPGRAFVTI, recognized by CTL begins at residue 807 of the fusion protein.