Figure 11.
Both motor proteins and DNA undergo major conformational changes during DNA packaging. Schematic of FRET between different dyes within the DNA and site of action of T4 gp49 (χ). Portal-bound Holliday junction resolvase (gp49) action releases compression from the Y-DNA substrates (A). Resolvase release of trapped Y-DNAs is also correlated with increased distance (∼0.6 nm, or 5.1 to 5.7 nm) between the terminase and the portal during packaging (B). Distances are measured from N and C termini of gp17 to the GFP–gp20 portal by FRET (C)(Dixit et al., 2011).