High-efficiency, temperature-sensitive suppression of amber mutations in Escherichia coli.
We have constructed a high-copy-number plasmid carrying an allele of the supD gene (supD43,74). The plasmid conferred temperature-sensitive suppression of amber mutations. Strains carrying the plasmid exhibited 50 to 60% suppression at 30 degrees C but little or no suppression at 42 degrees C. After a temperature shift from 30 to 42 degrees C the efficiency of suppression decreased gradually over a 60- to 90-min period before reaching the 42 degrees C steady-state level of suppression.
D004926:Escherichia coli / Q000235:genetics*; D009154:Mutation; D013489:Suppression, Genetic; D013696:Temperature