Role of Escherichia coli DNA polymerase IV in in vivo replication fidelity

J Bacteriol. 2004 Jul;186(14):4802-7. doi: 10.1128/JB.186.14.4802-4807.2004.


We have investigated whether DNA polymerase IV (Pol IV; the dinB gene product) contributes to the error rate of chromosomal DNA replication in Escherichia coli. We compared mutation frequencies in mismatch repair-defective strains that were either dinB positive or dinB deficient, using a series of mutational markers, including lac targets in both orientations on the chromosome. Virtually no contribution of Pol IV to the chromosomal mutation rate was observed. On the other hand, a significant effect of dinB was observed for reversion of a lac allele when the lac gene resided on an F'(pro-lac) episome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosomes, Bacterial / metabolism*
  • DNA Polymerase beta / metabolism*
  • DNA Repair
  • DNA Replication*
  • DNA, Bacterial / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / growth & development*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Gene Deletion
  • Genes, Reporter
  • Mutation
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism


  • DNA, Bacterial
  • DinB protein, E coli
  • Escherichia coli Proteins
  • DNA Polymerase beta
  • beta-Galactosidase