FIG. 4.

Disruption of the moxY gene via double-crossover recombination. (A) To disrupt the moxY gene, gene disruption vector pMOXY-DD was constructed as described in the text. The vector was linearized and then transformed into the wild-type strain SYS-4. The double-crossover recombination resulted in the replacement of most of the internal section of the target gene moxY with the ptrA gene. (B) PCR analysis of the moxY disruptant was conducted with genomic DNA of MOXY-DD-69 and the recipient strain SYS-4 by using different combinations of primers. Lanes: a, the moxY disruptant MOXY-DD-69; b, the recipient strain SYS-4; M, 1-kb molecular marker. The expected lengths of the PCR products are shown at the bottom of panel B.