V. cholerae FtsK Orienting Polar Sequences.

A. Growth competition of E. coli cells encoding FtsK hybrids. N: cells carrying a complete deletion of the C-terminal domain and linker region of FtsK^Ec; NLC^Ec: cells carrying full length FtsK^Ec; NLC^Vc and NLC^Hi: cells in which the C-terminal domain FtsK^Ec was replaced by the one of FtsK^Vc and FtsK^Hi, respectively. f: frequency of cells that the parental N strain fails to produce at each generation compared to the FtsK hybrids. B. 5′-GGGCAGGG-3′ inhibits recombination activation by FtsK^Vc. Plasmid recombination at E. coli dif by XerCD^Ec was induced with 0.5% arabinose. Ec[NRE]: FtsK_50C^Ec[NRE]; Vc[NRE]: FtsK^Vc[NRE]. KOPS-0: substrate without GGGCAGGG sequences; KOPS-2: substrate with triple overlapping GGGCAGGG sequences in the non-permissive orientation on both sides of the two dif sites. C. Scheme of the two V. cholerae chromosomes showing the distributions of the GGGCAGGG and GGGNAGGG motifs. Upper bars: motifs found in the leading strand; Lower bars: motifs found in the lagging strand. Number, frequency, skew and skew significance (p-skew) are indicated for each motif. Recently acquired genomic regions are indicated (superintegron, CTX and TLC prophages and the Vibrio Pathogenicity Island VPI).