Summary and comparison of the results for band shift assays and the in vivo and in vitro recombination tests.

aRecombination frequencies in vivo = white colonies/total colonies×100%.bRecombination frequencies in vitro = band densities of mutant with attR-L/band densities of wild-type integrase with attR-L×100%, assuming that 100% of the wild-type integrase in the reaction was active.cThe amount of free DNA substrate was plotted against concentrations of integrase to calculate the apparent binding affinities, Kd. NA, not applicable.The values reported are mean±SD of at least three curves.