Figure 4. Target orientation in the BPP-1 phage genome is not critical for recognition.

(A) Schematic of the BPP-1ΔATR phage genome with WT or inverted (VRInv) target sequences. A segment from position −133 upstream of VR to position +82 downstream of VR was inverted. VR-flanking primers used in the DGR homing assay are also indicated. (B) Target inversion had no significant effect on DGR homing activity. pMX-ΔTR23–96 or its RT-deficient derivative were used as donors for the indicated recipients and products from PCR-homing assays are shown. The diagram to the right shows primers used for the assay. Sequence analysis of VRInv homing products showed TG2 transfer from TR to VR, as well as adenine mutagenesis in 5/10 homing products amplified with primers P7 (Table 1) and P4, and 2/9 products amplified with P8 (Table 1) and P3 (Figure S7).