Multicopy suppression of the yeaZ(Ts), ygjD(Ts), and yjeE(Ts) mutant phenotypes. pACYC184 or one of its derivatives carrying yeaZ, ygjD, or yjeE was introduced into yeaZ(Ts), ygjD(Ts), and yjeE(Ts) mutant strains. These yeaZ, ygjD, and yjeE plasmids carry the E. coli chromosomal regions 1888076 to 1890587, 3203778 to 3208659 (the same result was obtained with the ygjD plasmid carrying the 3206931-to-3208659 region), and 4392209 to 4394317, respectively. Transformants were streaked on Antibiotic Medium 3 and incubated at 30°C, 37°C, or 42°C. The genotypes of the temperature-sensitive mutants are as follows: yeaZ(Ts), ΔyeaZ::Kmr ΔrecA::Tcr/mini-F (Smr)-yeaZ(Ts); ygjD(Ts), ΔygjD::Smr ΔrecA::Tcr/mini-F (Apr)-ygjD(Ts); yjeE(Ts), ΔyjeE::Smr ΔrecA::Tcr/mini-F (Apr)-yjeE(Ts).