Open AccessAnalysis of DNA Polymerases II and III in Mutants of Escherichia coli Thermosensitive for DNA Synthesis
Author(s) -
Malcolm L. Gefter,
Yukinori Hirota,
Thomas B. Kornberg,
James A. Wechsler,
C. Barnoux
Publication year - 1971
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.68.12.3150
Subject(s) - dna polymerase , dna polymerase ii , dna polymerase i , dna clamp , polymerase , dna replication , biology , microbiology and biotechnology , dna , mutant , dna polymerase mu , escherichia coli , dna polymerase delta , biochemistry , circular bacterial chromosome , gene , polymerase chain reaction , reverse transcriptase
A series of double mutants carrying one of the thermosensitive mutations for DNA synthesis (dnaA , B, C, D, E, F, and G) and thepol A1 mutation of DeLucia and Cairns, were constructed. Enzyme activities of DNA Polymerases II and III were measured in each mutant. DNA Polymerase II activity was normal in all strains tested. DNA Polymerase III activity is thermosensitive specifically in those strains having thermoscnsitive mutations at thedna E locus. From these results we conclude that DNA Polymerases II and III are independent enzymes and that DNA Polymerase III is an enzyme required for DNA replication inEscherichia coli .