Fig 3.
Linkage of transformation-defective phenotype to comRS mutation. Transformation was determined for three parallel AV2A (1) cultures (wild type [WT]), and parallel cultures of three independent ΔcomR comS::erm transformants of strain AV2A (1) (comRS). XIP-induced transformation (left) was determined at OD of 0.4 to 0.6 (left), by 40-min exposures to 1 μg/ml of DNA and 4 μM SinComS9–15. Endogenous development of competence (right) was determined as the maximum among three successive 40-min exposures to 1 μg/ml of DNA during growth from OD of 0.6 to 2. The dashed line indicates the limit of detection. Error bars represent standard deviations among triplicate determinations for each culture.