Bacterial strains and plasmids.

Provided by Jon Beckwith.

In the experiment with HU (Figure 2, Table 2) the LJ52 strain was used. It is referred to as MG1655 for simplicity.

Obtained from The Coli Genetic Stock Center, Yale University.

The nrdAB gene on the plasmid pSMG7 [50] used in this study was found to contain a point mutation in nrdB that leads to an amino acid change at position 367 (D367G). The plasmid is referred to as pIO5 in the text.