FIG. 2.

PCR tests that show replacement of wild-type alleles by deletion or insertion mutant alleles of the rdxA and frxA genes. The rdxA gene segment was PCR amplified from SS1 wild-type (lanes +), rdxAΔ111 (lanes Δ111), and rdxA::cam (lanes ::cam) strains using primers rdxA-F and rdxA-R. The frxA gene segment was PCR amplified from SS1 wild-type and frxA::kan (lanes ::kan) strains using primers frxA-F and frxA-R. Lane M indicates a 1-kb DNA ladder (size marker). Each of the lanes is from a separate transformant.