Fig. 1.

Head-on conflicts between transcription and replication cause increased association of helicase loader protein DnaB. Association of DnaB was assessed in ChIP-chip experiments in strains containing Pxis-lacZ inserted at thrC. Cells were grown in rich medium (LB) and sampled during exponential growth. The relative enrichment of a given chromosomal position is plotted on the y-axis vs the chromosomal position on the x-axis (in bp clockwise from oriC). Data are shown for the chromosomal region from ~3,240 kb through ~3,400 kb. The location of Pxis-lacZ inserted at thrC is indicated. Pxis-lacZ is head-on with replication. a. Data from cells expressing Pxis-lacZ (strain JMA264). b. Data from cells not expressing Pxis-lacZ (strain JMA201). These findings were verified by qPCR (Supplementary Fig. 3).