Figure 1.

E. coli chromosomal DNA insert in high copy plasmid clone pAQ5 and its derivatives (a) Clone pAQ5 containing sequence in the upp-purM-purN region was selected from an E. coli genomic DNA plasmid library for resistance to cell killing mediated by mutant topoisomerase I YpTOP1-D117N expressed in BW117N. PCR was used to amplify the intergenic sequence shown in (b) for cloning into pCR-TOPO-XL cloning vector in the construction of pInter. The sequence of the FNR and PurR binding site deleted in pInterD1 and pInterD2 is shown in (c).

Liu et al. BMC Microbiology 2011 11:261   doi:10.1186/1471-2180-11-261
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