The mechanism of template activation by exonuclease V.
In crude extracts from Escherichia coli cells the ATP-dependent exonuclease V was found to be most active in converting double-stranded DNA into a suitable template for DNA polymerase. This phenomenon was studied in some detail with isolated exonuclease V and T7 DNA polymerase. We found that, at ATP concentrations arount 1 mM, the exonuclease produces a broad spectrum of DNA fragments. One class of fragments is largely single stranded with hydrogen-bonded small primer sequences. These structures allow the synthesis of remarkably homogeneous polynucleotide strands by T7 DNA polymerase.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004261:DNA Replication; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D005092:Exonucleases / Q000378:metabolism*; D005838:Genotype; D007700:Kinetics; D013045:Species Specificity; D013698:Templates, Genetic
D000255:Adenosine Triphosphate; D004254:DNA Nucleotidyltransferases; D005092:Exonucleases