FIG 5.

Measurement of 3′-processing activities of integrase. 3′-processing activity was measured with enzyme concentrations fixed at 400 nM and various concentrations of immobilized LTR DNA. Time-resolved fluorescence (TRF) data were calculated as described in Materials and Methods, and the data were fitted in GraphPad Prism 5.0 to binding saturation curves to obtain values of LTR DNA K_m′ (A) and maximal 3′-processing activity (B). The data represent the means from at least 3 independent experiments, each performed in triplicate. Error bars represent the standard errors of the means (SEM). Asterisks indicate statistically significant differences. Statistical significance was calculated for individual pairs of data using a one-sample two-tailed t test with a statistical cutoff of P ≤ 0.05.