Fig. 5.
Substrate and motor dimensions and dynamics by FRET: (A) Increased FRET between stalled Y-stem DNA dye pairs supports B to A form compression; the gp49:Endonuclease VII X- or Y-resolvase decreases the Y-stem DNA FRET and allows completion of packaging. In the stalled anchored Y DNA the terminase moves toward the portal as judged by FRET increase between dye labeled terminase and (B) C-terminal GFP labeled gp20 portal containing proheads, and (C) N-terminal GFP labeled gp20 portal containing proheads that allow determination of the docking orientation in the two component prohead packaging motor.