DNA stimulates ATP-dependent proteolysis and protein-dependent ATPase activity of protease La from Escherichia coli.
The product of the lon gene in Escherichia coli is an ATP-dependent protease, protease La, that also binds strongly to DNA. Addition of double-stranded or single-stranded DNA to the protease in the presence of ATP was found to stimulate the hydrolysis of casein or globin 2- to 7-fold, depending on the DNA concentration. Native DNA from several sources (plasmid pBR322, phage T7, or calf thymus) had similar effects, but after denaturation the DNA was 20-100% more effective than the native form. Although poly(rA), globin mRNA, and various tRNAs did not stimulate proteolysis, poly(rC) and poly(rU) were effective. Poly(dT) was stimulatory but (dT)10 was not. In the presence of DNA as in its absence, proteolysis required concomitant ATP hydrolysis, and the addition of DNA also enhance ATP hydrolysis by protease La 2-fold, but only in the presence of casein. At much higher concentrations, DNA inhibited proteolysis as well as ATP cleavage. Thus, association of this enzyme with DNA may regulate the degradation of cell proteins in vivo.
D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D004247:DNA / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D009696:Nucleic Acids / Q000494:pharmacology; D010957:Plasmids; D049070:Protease La; D012697:Serine Endopeptidases; D013379:Substrate Specificity
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D009696:Nucleic Acids; D004247:DNA; D010450:Endopeptidases; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases; C483567:Lon protein, E coli; D049070:Protease La; D000251:Adenosine Triphosphatases