Figure 4.

rnhA and recG deletions exacerbate the ΔtopA phenotype. (A) No white colonies are observed on minimal medium when ΔtopA is combined with either rnhA or recG. (B-C) Overexpression of topB in a ptopA⁺/topA recG background allows formation of white colonies. The overexpression of topB in ptopA⁺/topA rnhA cells has no effect