title: Opposing effects of DNA on proteolysis of a replication initiator.
abstract: DNA replication initiation proteins (Reps) are subjected to degradation by cellular proteases. We investigated how the formation of nucleoprotein complex, involving Rep and a protease, affects Rep degradation. All known Escherichia coli AAA+ cytosolic proteases and the replication initiation protein TrfA of the broad-host-range plasmid RK2 were used. Our results revealed that DNA influences the degradation process and that the observed effects are opposite and protease specific. In the case of ClpXP and ClpYQ proteases, DNA abolishes proteolysis, while in the case of ClpAP and Lon proteases it stimulates the process. ClpX and ClpY cannot interact with DNA-bound TrfA, while the ClpAP and Lon activities are enhanced by the formation of nucleoprotein complexes involving both the protease and TrfA. Lon has to interact with TrfA before contacting DNA, or this interaction can occur with TrfA already bound to DNA. The TrfA degradation by Lon can be carried out only on DNA. The absence of Lon results with higher stability of TrfA in the cell.
authors: Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Gdansk, Poland.
authors: Slawomir
authors: S
authors: Kubik
authors: Katarzyna
authors: K
authors: Wegrzyn
authors: Marcin
authors: M
authors: Pierechod
authors: Igor
authors: I
authors: Konieczny
mesh_terms: D049069:ATP-Dependent Proteases / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D049071:Endopeptidase Clp / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D049070:Protease La / Q000378:metabolism; D020836:Protein Structure, Quaternary; D059748:Proteolysis
chemical_list: D029968:Escherichia coli Proteins; C067405:TrfA protein, E coli; D004247:DNA; D049069:ATP-Dependent Proteases; C483567:Lon protein, E coli; D049070:Protease La; D049071:Endopeptidase Clp