Reduced synthesis of β-galactosidase in Escherichia coli infected with phage φX174

Abstract

The synthesis of β-galactosidase (EC 3.2.1.23; β-D-galactoside galactohydrolase) in E. coli was repressed as a result of infection with single-stranded DNA phage φX174. Evidence is presented to show that this repression was not due to the restricted entry of the inducer molecules into the infected cells but to some phage-specified product(s). It was further shown that either the infected cells synthesized a fewer number of enzyme-specific mRNA or all such molecules were translated with a reduced efficiency; the half-lives of the mRNA's remained more or less unaffected.