Efficient pseudotyping of MLV- and HIV-derived vectors with wild-type or mutant F and H MV-gps. (A) Schematic presentation of wild-type or mutant F and H gps from the Edmonston MV strain. The double vertical lines (//) separate the transmembrane sequences (TM) from the cytoplasmic domain (cyt-tail). The single line (/) indicates that part of TM is not shown. HΔ15, HΔ20, and HΔ24 represent H mutants with progressive deletions of the cytoplasmic tail. H97E contains a single amino acid mutation at position 97 in the TM region of wt H. FΔ30 contains only 3 residual amino acids of the F wt cytoplasmic tail. (B) 293T cells were incubated with serial dilutions of GFP-encoding MLV or HIV vectors that were pseudotyped with Hwt, HΔ15, HΔ20, HΔ24, or H97E in combination with Fwt or FΔ30. Control incubations were performed with RDTR gp–pseudotyped vectors. Cells were analyzed for GFP expression 72 hours after transduction by FACS analysis. Titers are expressed as TU/mL. Data are shown as means plus or minus SD; n = 6.