Role of adenine nucleotides, molecular chaperones and chaperonins in stabilization of DnaA initiator protein of Escherichia coli.
DnaA protein of Escherichia coli is a sequence-specific DNA binding protein required for the initiation of DNA replication from the chromosomal origin, oriC, and of several E. coli plasmids. At a moderate ionic strength, purified DnaA protein has a strong tendency to aggregate; the self-aggregate form is inactive in DNA replication. Binding of ATP or ADP to DnaA protein protected it from aggregation to maintain its replication activity. AMP or cyclic AMP had no protective effect. The molecular chaperone DnaK protected DnaA protein from aggregation with or without ATP. DnaJ and GrpE were not stimulatory. Chaperonins GroEL and GroES were also able to prevent aggregation but only in the presence of ATP. The studies presented here show that for DnaA protein to be active in the initiation of DNA replication, it must be prevented from forming a self-aggregate by the binding of adenine nucleotides, and/or by the action of molecular chaperones.
Department of Molecular and Cellular Biology, Faculty of Biotechnology, University of Gdansk, Kladki 24, 80-822 Gdansk, Poland.
B
B
Banecki
J M
JM
Kaguni
J
J
Marszalek
D000227:Adenine Nucleotides / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018835:Chaperonin 10 / Q000235:genetics* / Q000378:metabolism; D018834:Chaperonin 60 / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding
D000227:Adenine Nucleotides; D001426:Bacterial Proteins; D018835:Chaperonin 10; D018834:Chaperonin 60; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; C063842:dnaK protein, E coli