Processing of stalled replication fork under thymine starvation and its relationship with thymineless death in Escherichia coli

In this work we characterized the mechanism by which the stalled replication forks generated under depletion of deoxynucleotides (dNTP) are processed and the relationship of the fork processing with the viability of the cell. RFR occurred at the stalled forks generated by hydroxyurea treatment (chemical inactivation of NDP reductase), was impaired under incubation of nrdA 101 mutant at 42 degrees C (structural inactivation of NDP reductase), and did not take place under thymine starvation. Viability experiments confirmed RFR model predictions and supported that thymineless death (TLD) is related with the processing of the stalled forks. Furthermore we show that TLD conditions Suppressor generated stalled forks processed by RFR. We Suggest is that the connection between DNA replication and TLD is through the fate of the stalled replication forks when thymine is removed.