FIG. 2.

Fv1 activity of C-terminal deletion mutants. FACS profiles illustrating the effect of the C terminus on restriction of B-tropic tester virus are shown. EGFP expression is shown on the x axis; EYFP expression is shown on the y axis. The percentages given each indicate the proportion of EYFP-positive, i.e., B-MLV-infected, cells in the EGFP-negative (Fv1⁻) and the EGFP-positive (Fv1⁺) subpopulation. Wild-type Fv1ⁿ (A), mutant Fv1^bΔ441–459 (B), wild-type Fv1^b (C), and mutant Fv1^bΔ411–459 (D) were introduced. The amount of restriction decreased from the full restriction shown in panel A to the partial restriction shown in panel B the slight restriction shown in panel C, and the lack of restriction shown in panel D. The percentages given are typical of the values for each level of restriction.