title: Bacteriophage N4-coded 5'----3' exonuclease. Purification and characterization.
abstract: Bacteriophage N4 DNA replication requires the activity of a phage-induced exonuclease. We show here that the activity is phage coded. We have purified this enzyme to apparent homogeneity. It has a denatured molecular weight of 45,000 and exists in solution as a dimer. Duplex DNA is the preferred substrate which it degrades in a 5'----3' direction to 5' mononucleotides by a distributive mechanism. The enzyme does not act at a nick or a gap; indeed, it requires an end for activity. A possible role for this exonuclease in N4 replication is discussed.
mesh_terms: D003090:Coliphages / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V