[Induction of the SOS-like system in Rec-mutants of Bacillus subtilis]

Influence of the recE1, recB2, recB3, recB19, recF15, recF18, recL16, recM13 and recM27 mutations of the induction of the SOS-like system component, i. e. the RecE protein of Bacillus subtilis was studied by RIA-dot-blot method in UV-irradiated or treated by nalidixic acid cells. These agents caused a significant increase in the wild type (rec+) cells but did not stimulate the RecE synthesis in the rec mutants tested. The two exceptions were recB2 and recF18 mutants treated by nalidixic acid. The tsi23 mutation caused thermoinduction of phi 105 bacteriophage in the rec+ genetic background while no prophage particles were induced in the recE, recF, recL, recM mutants. The data suggest that the genetic damage of several rec genes including recB, recE, recF, recL and recM can block induction of the SOS-like system of Bacillus subtilis.