Figure 3. Topo III overproduction and recQ deletion are epistatic to recA deletion in correcting the growth defect of the topA gyrB(Ts) strain.
Spot tests were performed at the indicated temperatures. The LB plates were incubated for the indicated times. The strains used are all derivatives of RFM475 (gyrB(Ts) ΔtopA). They are: a) CT150 (RFM475 ΔrecQ), SB265 (RFM475 ΔrecA) and VU492 (ΔrecQ ΔrecA); b) VU118 (RFM475/pPH1243), SB265 (RFM475 ΔrecA) and VU479 (SB265/pPH1243); c) VU118 (RFM475/pPH1243), CT150 (RFM475 ΔrecQ) and VU464 (CT150/pPH1243); d) RFM475, SB362 (RFM475 lexA3) and SB265 (RFM475 ΔrecA); e) SB362 (RFM475 lexA3), CT150 (RFM475 ΔrecQ) and VU501 (RFM475 ΔrecQ lexA3); f) RFM475 and SB262 (RFM475 recB::Tn10). Cells carrying pPH1243 were grown in the presence of IPTG to overproduce topo III.