Figure 4.

Biochemical analysis of recombinant fragments of amino acids 1–77 and 1–170 of the P element transposase. DNaseI protection footprinting analysis on the high-affinity, specific transposase binding site using increasing amounts of recombinant protein: (A) amino acids 1–77 or (B) amino acids 1–170, identified from the GFP solubility screen. Lanes 1–4 are chemical DNA sequencing markers; Lanes 5 and 10 have no protein; and Lanes 6–9 have increasing amounts of recombinant protein. The recombinant fragment amino acids 1–170 was shown to be a dimer by EGS chemical crosslinking. 375 pmoles of protein are in each lane with 0, 0.18, 0.36, 0.75, 1.5, or 3 mM crosslinking reagent in a 15 μL volume. (C) shows an 18% SDS-P.A.G.E. protein gel stained with coomassie blue. (D) an immunoblot, probed with anti-His₆ antibody (Santa Cruz Biotechnology). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]