The role of a trypsin-sensitive factor in multiplicity reactivation with heat-disrupted phage

Abstract

Heat-disrupted T2 or T4 phage can infect E. coli spheroplasts. Multiplicity reactivation can take place in spheroplasts infected with heat-disrupted T2 or T4 phage which have been irradiated with ultraviolet light. Such reactivation failed to occur with trypsin digested preparations. Similar results were obtained in spheroplasts cross-infected with disrupted T2 and T4 phage; thus the reactivation of T2 phage which has been irradiated with ultraviolet light, heated and then digested with trypsin, can be observed in spheroplasts simultaneously infected with heated T4 phage. The reactivating ability of this heated T4 phage was greatly inhibited by digestion with trypsin but not with deoxyribonuclease or ultraviolet light irradiation. From these results it can be inferred that the trypsin-sensitive factor, present in phage DNA preparations, is required for multiplicity reactivation and that multiplicity reactivation of disrupted T2 phage can also take place with the trypsin-sensitive factor from T4 phage DNA preparations.