Mechanism of o-phenanthroline mediated inhibition of E. coli DNA polymerase I : formation of template-primer-metal-phenanthroline complexes with resultant loss of catalytic activity.
Inhibition of E. coli DNA polymerase I activity by 1,10 phenanthroline in the absence of reducing agents requires a high concentration of inhibitor (1-10 mM) depending upon the template primer used to direct the synthesis. We find that o-phenanthroline, unlike its non-chelating analogue, forms a divalent cation mediated complex with template-primers. Enzyme bound to such complexes is unable to catalyse either polymerization or nuclease functions.
D003300:Copper / Q000378:metabolism; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors*; D004261:DNA Replication / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D008274:Magnesium / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology*; D013698:Templates, Genetic
D010618:Phenanthrolines; C001635:ferroin; D003300:Copper; D004256:DNA Polymerase I; D008274:Magnesium