Processivity of DNA exonucleases.
A homopolymer system has been developed to examine the digestion strategies of DNA exonucleases. Escherichia coli exonuclease I and lambda-exonuclease, are processive enzymes. However, T7 exonuclease, spleen exonuclease, E. coli exonuclease III, the 3' leads to 5'-exonuclease of T4 DNA polymerase, and both the 3' leads to 5' and the 5' leads to 3' activity of E. coli DNA polymerase I dissociate frequently from the substrate during the course of digestion. Regions of duplex DNA are a dissociation signal for exonuclease I.
D000818:Animals; D003090:Coliphages / Q000201:enzymology; D003851:Deoxyribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D005092:Exonucleases / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D013154:Spleen / Q000201:enzymology
D003851:Deoxyribonucleases; D005092:Exonucleases