Deletion of IXR1 leads to decreased dNTP levels.

(A) dNTP levels are decreased in ixr1Δ (TOY736), increased in ixr1Δ sml1Δ (TOY714) compared to wild-type (W1588-4C), but lower than in sml1Δ (U952-3B). Values shown are the average from two independent experiments with the minimum and maximum values represented as error bars. (B) dNTP levels increase in ixr1Δ (TOY736, black triangles) during the treatment with 0.2 mg/L 4-NQO, but less than in a wild-type strain (W1588-4C, open circles). Values shown are the average from two independent experiments with the minimum and maximum values represented as error bars. (C) ixr1Δ (TOY736) has a higher frequency of petite formation than a wild-type strain (W1588-4C). (D) ixr1Δ (TOY736) is more sensitive to HU than a wild-type strain (W1588-4C).