A prepriming DNA replication enzyme of Escherichia coli. I. Purification of protein n': a sequence-specific, DNA-dependent ATPase.
Protein n', an enzyme essential for in vitro conversion of single-stranded phiX174 DNA to the duplex replicative form, has been purified about 16,000-fold from Escherichia coli. The enzyme is a single polypeptide chain with a native molecular weight of 76,000; about 70 enzyme molecules are present in an E. coli cell. Nearly homogeneous preparations display an ATPase (dATPase) activity which depends on a unique sequence in the phiX174 DNA. Replicative activity of n' protein and its phiX174 DNA-dependent ATPase activity were present in a constant ratio during the latter stages of purification, upon sedimentation in a glycerol gradient, and during heat inactivation. Further studies of the properties of protein n' are presented in a succeeding paper.
D000251:Adenosine Triphosphatases / Q000302:isolation & purification* / Q000378:metabolism; D010584:Bacteriophage phi X 174; D001483:Base Sequence; D004265:DNA Helicases / Q000302:isolation & purification* / Q000378:metabolism; D004261:DNA Replication; D004279:DNA, Viral; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D008970:Molecular Weight; D013379:Substrate Specificity
D004279:DNA, Viral; D000251:Adenosine Triphosphatases; D004265:DNA Helicases