N155H IN possesses slower assembly and concerted integration kinetics in comparison to wt IN. In panel (A) wt IN (20 nM) and in panel (B) N155H IN (30 nM) were pre-assembled with 5′-32P end-labeled 1.6 kb U5 blunt-ended DNA (0.5 nM) for 15 min at 14°C. Supercoiled DNA (1.5 nM) was added to study the assembly kinetics of SC, H-SC, and STC from 0 min to 180 min at 37°C. (C) Kinetics of formation of SC, H-SC, and STC with wt IN. The percentage of input DNA incorporated into each nucleoprotein complex versus time was plotted. (D) Kinetics of formation of SC, H-SC, and STC with N155H IN. (E) Aliquots of the above experiments with wt and N155H IN were deproteinized and the quantities of FS products were determined and plotted. The total quantities of FS products after 180 min were 35% and 27%, respectively.