Regulation of argF mRNA synthesis,performed in vitro

The specific synthesis of $\text{arg}$F mRNA directed by the $\text{arg}$F gene carried on the specialized transducing bacteriophage $\text{λh80C}{}_1\text{857darg}$F, performed $\text{in vitro}$, is described with the use of an S180 extract from a strain carrying $\text{arg}$R^?. Synthesis of $\text{arg}$F mRNA is biphasic at approximately 7 minutes. The regulation of $\text{arg}$F mRNA synthesis by the specific arginine holorepressor present in an S180 extract prepared from a strain carrying the $\text{arg}$R⁺ allele is described.