Fig 6.

An HLH peptide binds to the portal protein. (A) Schematic of the recombinant HLH peptide constructs. The WT and scrambled sequences of the HLH motif (as shown) are fused in-frame to the C terminus of RB69 Soc (34). (B) Inhibition of in vitro DNA packaging by HLH peptide. In vitro DNA packaging assays were performed as described in Materials and Methods (20). Proheads (4 × 10⁹ particles) were first incubated with HLH peptide (WT, scrambled [SCR], or F348A) for 15 min, after which the rest of the packaging components were added. The agarose gel shows DNA packaging with 1 μM gp17 alone (control lanes 1 and 2) or in the presence of WT peptide (lanes 3 and 4), scrambled peptide (lanes 5 and 6), or F348A peptide (lanes 7 and 8). (C) Relative amounts of DNA packaged by reactions in panel B.