Figure 4.

The OB-mutant Pol III HE is deficient in lagging strand synthesis. (A) Scheme of replisome assembly on a minicircle replication fork substrate using DnaB helicase and wt or OB-mutant Pol III HE (B) Leading (left panel) and lagging (right panel) strands can be selectively labelled depending on whether α-³²P dATP or α-³²P dTTP is present during synthesis. Aliquots were removed at the indicated times and analysed in a 1.2% alkaline agarose gel followed by autoradiography. The relative level of DNA synthesis at 320 s is shown at the bottom of the gel.