oX-174 in a Cell-free System

A cell-free system having high RNA and protein synthesizing activities was prepared from Escherichia coli Q 13. When the replicative form DNA of bacteriophage OX-174 was added to the system, remarkable stimulation of the RNA and protein synthesis was observed. The synthesized RNA was only hybridized with the "minus " strand of the replicative form DNA, showing that the nucleotide sequence of the minus strand was transcribed by RNA— polymerase. The protein synthesized in this system was identified by various methods, and it was demonstrated that the major product was the phage-coat protein. The significance of the above observations is discussed in relation to the mechanism of expression of the genetic information encoded in the phage DNA