FIG. 1.

Analysis of deletion mutants in the 5′ UTR for the expression of Gag and Pol proteins. (A) Wild-type pCgp-1 gag and pol expression construct and deletion mutants in the 5′ UTR. The major 5′ SD, the primer binding site (pbs), and the poly(A) signal (pA⁺), which was derived from the bovine growth hormone gene and is present in the pcDNA vector (Invitrogen), are indicated. The numbering of the deletions (Δ) is relative to the start of transcription (+1). The deletions in the constructs are marked by stippled lines. (B) Analysis of Gag and Pol protein expression levels in 293T cells transfected with the pCgp plasmids. Cellular lysates were reacted with PFV Gag and Pol antibodies in an immunoblot. M, relative molecular mass standards in kilodaltons.