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

Biochem Biophys Res Commun. 1983 Sep 15;115(2):567-76. doi: 10.1016/s0006-291x(83)80182-x.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Copper / metabolism
  • DNA Polymerase I / antagonists & inhibitors*
  • DNA Replication / drug effects
  • Escherichia coli / enzymology*
  • Magnesium / metabolism
  • Phenanthrolines / pharmacology*
  • Templates, Genetic


  • Phenanthrolines
  • ferroin
  • Copper
  • DNA Polymerase I
  • Magnesium