Joining of DNA Strands by DNA Ligase of E. coli

Enzymes which covalently join DNA strands have been isolated in the past two years from uninfected E. coli (Gellert, 1967; Olivera and Lehman, 1967a; Zimmerman et al., 1967; Gefter et al., 1967) and from E. coli infected with phage T4 (Weiss and Richardson, 1967a; Cozzarelli et al., 1967; Becker et al., 1967). It is likely that these DNA ligases have a role in DNA repair and recombination. They have also recently been implicated in the process of DNA replication (Okazaki et al., 1968; Newman and Hanawalt, 1968).