Abstract
The covalent closing of hydrogen-bonded lambda DNA circles in Escherichia coli extract was observed to require DNA polymerase I, recBC enzyme and ATP. This covalent closing activity was lost in strains harbouring a mutation in one of the genes responsible for production of the enzymes mentioned above, and was recovered by combining these mutant extracts. ATP could be replaced with dATP, but not appreciably with any of the other nucleoside triphosphates. High concentrations of ATP inhibited the closure. K+ or NH4+ (0.2M) was required for optimal activity and NMN was a strong inhibitor.
MeSH terms
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Adenosine Triphosphate / pharmacology
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Bacteriophage lambda / drug effects
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Bacteriophage lambda / metabolism
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DNA Ligases / metabolism
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DNA Polymerase I / metabolism*
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DNA, Circular / metabolism*
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DNA, Viral / metabolism*
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DNA-Directed DNA Polymerase / metabolism*
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Deoxyribonucleases / metabolism*
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Escherichia coli / genetics
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Escherichia coli / metabolism*
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Escherichia coli Proteins*
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Exodeoxyribonuclease V
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Exonucleases / metabolism*
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Mutation
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Nicotinamide Mononucleotide / pharmacology
Substances
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DNA, Circular
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DNA, Viral
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Escherichia coli Proteins
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Nicotinamide Mononucleotide
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Adenosine Triphosphate
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DNA Polymerase I
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DNA-Directed DNA Polymerase
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Deoxyribonucleases
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Exonucleases
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Exodeoxyribonuclease V
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exodeoxyribonuclease V, E coli
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DNA Ligases