Quantitative analysis of the bacteriophage Qβ infection cycle

In this study, the infection cycle of bacteriophage Qβ was investigated. Adsorption of bacteriophage Qβ to Escherichia coli is explained in terms of a collision reaction, the rate constant of which was estimated to be 4 × 10− 10 ml/cells/min. In infected cells, approximately 130 molecules of β-subunit and 2 × 105 molecules of coat protein were translated in 15 min. Replication of Qβ RNA proceeded in 2 steps—an exponential phase until 20 min and a non-exponential phase after 30 min. Prior to the burst of infected cells, phage RNAs and coat proteins accumulated in the cells at an average of up to 2300 molecules and 5 × 105 molecules, respectively. An average of 90 infectious phage particles per infected cell was released during a single infection cycle up to 105 min.