Ligase activity of lig- bacteria infected with mu bacteriophage at non-permissive temperatures]

Infection of bacteria E. coli lig ts7, which contain a thermosensitive ligase by phage Mu results in a decrease in the sensitivity to the lethal action of ultraviolet irradiation and stimulation of lysogenization among the surviving cells. These observations suggest the existence of a phage coded ligase which has the character of an integrase.