Figure 2.

RecO, RecF, and DdrB proteins are required for transformation in cells devoid of DprA. D. radiodurans cells were transformed with (A) 200 ng genomic DNA from a [Rif^R] (GY 11733) strain or (B) with 200 ng of p11559 plasmid DNA conferring spectinomycin resistance. The results are the average of at least five independent experiments. (a): The frequency of [Rif^R] or [Spec^R] transformants is as low as the spontaneous frequency of [Rif^R] or [Spec^R] mutants. Statistically significant differences of transformation frequencies of the mutants, compared with those observed in wild type strain, were calculated using the non-parametric Mann Whitney test: ***P < 0.001; ****P < 0.0001; ns if P > 0.5.