Figure 1.
Envelope glycoproteins derived from the env genes of HIV-1 and MuLV. Plasmid pEnv encodes the wild-type envelope glycoproteins of HIV-1 consisting of a total of 856 amino acids (strain BH10; ref. 22). The membrane spanning region (M) is located between amino acids 681 and 705 (23). Plasmid pTr712 encodes a truncated variant of the TM protein due to the insertion of a stop codon at amino acid position 712 by site-directed mutagenesis. The coding region of the MuLV-derived envelope proteins is shown for comparison.