The dnaB-dnaC replication protein complex of Escherichia coli. II. Role of the complex in mobilizing dnaB functions.
The dnaC protein of Escherichia coli, by forming a complex with the dnaB protein, facilitates the interactions with single-stranded DNA that enable dnaB to perform its ATPase, helicase, and priming functions. Within the dnaB-dnaC complex, dnaB appears to be inactive but becomes active upon the ATP-dependent release of dnaC from the complex. With adenosine 5'-(gamma-thio)triphosphate substituted for ATP, the dnaB-dnaC complex does not direct dnaB to its targeted actions. Excess dnaC inhibits dna beta actions and augments the ATP gamma S effects. In the dnaA protein-driven initiation of duplex chromosome replication, dnaB is introduced for its essential helicase role via the dnaB-dnaC complex. Similarly, when the dnaA protein interacts nonspecifically with single-stranded DNA, the dnaB-dnaC complex is essential to introduce dnaB for its role in primer formation by primase.
Wahle
E
E
Department of Biochemistry, Stanford University School of Medicine, California 94305-5307.
Lasken
R S
RS
Kornberg
A
A
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D003570:Cytidine Triphosphate / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances
D001426:Bacterial Proteins; D046911:Macromolecular Substances; C022571:adenosine 5'-O-(3-thiotriphosphate); D003570:Cytidine Triphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D004265:DNA Helicases