FIG. 1.
Localization of the TRX protein in the BX-C. (Top) A diagram of the molecular organization of the BX-C. Map coordinates (in kilobases) are based on the complete sequence of the BX-C (22). The Ubx, abdA, and AbdB transcription units and regulatory regions are shown above the DNA. PREs (7, 16, 32, 39) and Pc protein binding regions (43) are shown beneath the DNA as filled bars and arrows, respectively. The TRX protein binding regions are indicated by arrows above phage clones that contain TRX binding fragments, which are shown as horizontal lines. (Bottom) Phage clones are indicated by numbers. Equal amounts (∼1 μg) of each of the 27 overlapping λ Charon clones (2) were digested with EcoRI and transferred onto a nylon membrane. The membrane was hybridized with 32P-labeled PCR-amplified fragments of genomic DNA obtained after two rounds of amplification-immunoprecipitation with TRX antibody (see Materials and Methods). Positions of molecular weight markers are indicated on the left. Asterisks indicate two bands also seen in control experiments with preimmune serum that were probably due to repeats in genomic DNA (these bands were not seen in the preimmune serum control lane when cloned phage DNA was used for immunoprecipitation, as in Fig. 2).