Structural basis for proofreading during replication of the Escherichia coli chromosome

Samir Hamdan, Paul D. Carr, Susan E. Brown, David L. Ollis, Nicholas E. Dixon*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

126 Scopus citations


The ε subunit of the Escherichia coli replicative DNA polymerase III is the proofreading 3′-5′ exonuclease. Structures of its catalytic N-terminal domain (ε186) were determined at two pH values (5.8 and 8.5) at resolutions of 1.7-1.8 Å, in complex with two Mn(II) ions and a nucleotide product of its reaction, thymidine 5′-monophosphate. The protein structure is built around a core five-stranded β sheet that is a common feature of members of the DnaQ superfamily. The structures were identical, except for differences in the way TMP and water molecules are coordinated to the binuclear metal center in the active site. These data are used to develop a mechanism for ε and to produce a plausible model of the complex of ε186 with DNA.

Original languageEnglish (US)
Pages (from-to)535-546
Number of pages12
Issue number4
StatePublished - 2002
Externally publishedYes


  • Binuclear metallohydrolase
  • DNA polymerase III
  • DNA replication
  • DnaQ
  • Exonuclease (3′-5′)
  • Manganese metalloenzyme
  • X-ray crystallography

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology


Dive into the research topics of 'Structural basis for proofreading during replication of the Escherichia coli chromosome'. Together they form a unique fingerprint.

Cite this