Table 2.

Apparent binding affinities by integrase for mutant attB sites

attB Site; position of mutation	Nature of mutation	Mean integrase concentration for 50% binding ± SDa (nM)
Wt	–	61.3 ± 12.7
−/+2	C-2A:G+2T	56.7 ± 16.1
−2	C-2G	55.7 ± 3.5
+2	G+2C	58.3 ± 6.7
−/+15	T-15C:C+15G	127.7 ± 24.2
−15	T-15C	68.3 ± 5.8
+15	C+15G	72.7 ± 5.5
−/+16	G-16T:G+16A	61.3 ± 12.1
−16	G-16T	66.0 ± 5.3
+16	G+16A	53.3 ± 6.1
−/+18	G-18C:A+18G	189.7 ± 30.7
−18	G-18C	194.7 ± 17.1
+18	A+18G	186.3 ± 19.8
Partially symmetrical site	2L(+12 - +18)	61.7 ± 5.7

^aMeans and SDs were calculated from the integrase concentrations required for 50% binding from three separate binding experiments.