Figure 4From: On the viability of Escherichia colicells lacking DNA topoisomerase IrnhA 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 effectBack to article page