Suppressor mutations rescue the growth of Escherichia coli A49 at the nonpermissive temperature. (A) Growth of the E. coli A49 suppressor strains carrying (i) amplifications of rnpA49 or rnpB or loss-of-function mutations in (ii) rnr or (iii) lon on LB-agar after 24 h incubation at the nonpermissive temperature (42°C). DA5438 is E. coli MG1655 carrying the wild-type rnpA allele; DA61546 is the E. coli A49 parental strain carrying the ts rnpA49 allele. Additional control strains containing kanR deletion cassettes from the KEIO collection in the parental DA61546 A49 background are included for comparison. (B) Relative exponential phase growth rates of the E. coli A49 suppressor strains and relevant control strains as compared to the DA61546 A49 parental strain (set to 1) at the corresponding temperature. Growth measurements were performed in LB medium at both 30°C (permissive temperature) and 40°C (sublethal temperature). The values reported represent the mean of at least three independent biological replicates (with two technical replicates each); error bars represent the standard deviation of the mean.
