Figure 4

Generation of the Rps1 -k-3 through intramolecular recombination. Locations of Rps1-k-1 and Rps1-k-2 on the GS_43D16 sequence are shown. Partial BamHI digested GS_43D16 DNA was cloned into the binary vector pTF101.1 and a library of binary clones was obtained. The library was screened for LRR sequences. Binary clone p43-10 contained the Rps1-k-3 gene, which is not present in GS_43D16 (Figure 3). This gene was presumably originated from intramolecular recombination in E. coli. Three BamHI (B) sites involved in generation of the Rps1-k-3 [1] are shown on the map. Solid line shows the region cloned in p43-10 and broken line indicates the region not found in p43-10. Presumably this region was lost during the recombination process in E.coli. The possible recombination process involved in the evolution of Rps1-k-3 is shown at lower part of the figure. The two identical 174 bp sequences of Rps1-k-1 (red line) and Rps1-k-2 (black line) involved in the recombination process are shown within the blue open circle (21,980 through 22,154 of Rps1-k-1 and 46,473 through 46,647 of Rps1-k-2 in the Rps1-k region shown in Figure 3B). The proposed model for the recombination event in E. coli is based on the article by Weisberg and Adhya [65].