Purification and characterization of bacteriophage N4-induced DNA polymerase.
Coliphage N4 replication is independent of most host DNA replication functions except for the 5'----3' exonuclease activity of polA, DNA ligase, DNA gyrase, and ribonucleotide reductase (Guinta, D., Stambouly, J., Falco, S. C., Rist, J. K., and Rothman-Denes, L. B. (1986) Virology 150, 33-44). It is therefore expected that N4 codes for most of the functions required for replication of its genome. In this paper we report the purification of the N4-coded DNA polymerase from N4-infected cell extracts by following its activity on a gapped template and in an in vitro complementation system for N4 DNA replication (Rist, J. K., Pearle, M., Sugino, A., and Rothman-Denes, L. B. (1986) J. Biol. Chem. 261, 10506-10510). The enzyme is composed of one polypeptide, Mr 87,000. It is most active on templates containing short gaps synthesizing DNA with high fidelity in a quasi-processive manner. A strong 3'----5' exonuclease activity is associated with the DNA polymerase polypeptide. No 5'----3' exonuclease or strand-displacing activities were detected.
Lindberg
G K
GK
Department of Biochemistry and Molecular Biology, University of Chicago, Illinois 60637.
Rist
J K
JK
Kunkel
T A
TA
Sugino
A
A
Rothman-Denes
L B
LB
D003090:Coliphages / Q000201:enzymology*; D011088:DNA Ligases / Q000378:metabolism; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000096:biosynthesis / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D008970:Molecular Weight; D013696:Temperature
D004259:DNA-Directed DNA Polymerase; D011088:DNA Ligases