FIG. 1.

Schematic of Gag expression constructs. The wild-type RSV Gag polyprotein is illustrated at the top, with MA, p2, p10, CA, NC, and PR domains indicated. The wild-type (WT) p10 NES sequence is shown above the schematic, and mutant sequences are indicated below the schematic. Critical hydrophobic residues are indicated in bold. GagΔPR lacks the entire PR domain. For each Gag fusion protein, the PR sequence was replaced with spectral variants of GFP: YFP, CFP, mCherry, and the N- or C-terminal domain of Venus (VN and VC). Gag.ΔNC has a deletion of amino acid residues 495 to 577 in the NC domain. Gag.Zip has the leucine zipper domain of the human CREB binding protein (Zip) substituted for the NC domain. The MLV Gag polyprotein, consisting of MA, p12, CA, and NC, is shown fused to the N- or C-terminal domain of Venus.