On the localization of the origin of DNA replication in E. coli

Samuel Litwin, Neville R. Kallenbach

Research output: Contribution to journalArticlepeer-review


The process of DNA replication in procaryotes with a circular chromosome is analyzed in terms of a stochastic model including the following features: (1) heterogeneity in the rate of DNA synthesis from cell to cell in a culture, (2) any degree of positive or negative correlation between mother and daughter cells and (3) drift of the origin and terminus in a chromosome from one generation to the next over a specified region or set of points in the chromosome. The model is applied to experimental data on E. coli cells in balanced growth, assuming the bidirectional replication process can be simulated by independent unidirectional processes along each arm. Comparison of calculated recovery profiles for label in a density pulse experiment reveals that there is remarkable latitude for drift of the origin from one generation to the next, with succeeding rounds capable of initiation at any site within a region of one half the total chromosomal length. The marker frequencies of genes at different positions on the chromosome measured by "equilibrium" assays similarly can be reconciled with unidirectional or bidirectional processes with a wandering origin. If as is suggested by results from kinetic experiments on populations with aligned chromosomes replication is bidirectional with a unique fixed site of origin, the results of the label recovery experiments are inconsistent with the available evidence for heterogeneity in replication times and growth rates.

Original languageEnglish (US)
Pages (from-to)747-760
Number of pages14
JournalJournal of Theoretical Biology
Issue number4
StatePublished - Feb 21 1977

ASJC Scopus subject areas

  • Statistics and Probability
  • Modeling and Simulation
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology
  • General Agricultural and Biological Sciences
  • Applied Mathematics


Dive into the research topics of 'On the localization of the origin of DNA replication in E. coli'. Together they form a unique fingerprint.

Cite this