A study was made of the kinetics of excision of thymine-containing pyrimidine dimers from prelabeled phage T4 during infection of Escherichia coli. In wild-type hosts excision of dimers was observed immediately after infection, but ceased at some maximal level five to seven minutes later. In host cells defective in DNA polymerase I (either polymerizing activity, 5′→3′ exonuclease activity, or both) there was a significant reduction in both the rate and the final extent of excision during the first five to seven minutes after infection. Mutation in the recB gene was found to have no effect on the kinetics of excision. The kinetics of dimer excision in cells infected with a T4 mutant defective in DNA synthesis were no different from that observed with wild-type phage. Thus the cessation of dimer excision at about five to seven minutes after infection is not obviously related to the onset of phage DNA replication.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Molecular Biology|
|State||Published - Nov 25 1976|
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology