Restoration of DNA synthesis at non-permissive temperature and of UV resistance induced by bacteriophage Mu in Escherichia coli lig ts7 strain.

Infected by Mu, a mutant of E. coli, carrying the mutation lig ts7 shows a UV sensitivity intermediate between that of the uninfected lig-strain and that of the parental lig+ strain. At non-permissive temperature bacterial DNA replication is restored upon infection. These results suggest that DNA-ligase activity is coded for by the phage Mu genome.