Early events and mechanisms in the induction of bacterial SOS functions: analysis of the phage repressor inactivation process in vivo.

Different inducing agents and treatments produced distinctly different kinetic patterns of inactivation of prophage repressor molecules. The different patterns were related to differences in the initial altered states of DNA that were produced. The timing of appearance of DNA degradation was correlated with the time needed for repressor inactivation. These characteristics suggest that all the inducing treatments lead to the formation of a final predegradative DNA structure(s) (probably involving scissions) that is acted on by specific DNases, including the recBC DNase, to produce the signals for the induction of prophage.