TABLE 1.

Kappa (κ) values for analogs of three adenosines in the U1A stem-loop binding region

	Complex 1	Complex 2	Complex 3	Complex 4	Complex 5
A65	1.2 ± 0.3	1.3 ± 0.3	1.1 ± 0.2	1.3 ± 0.5	1.2 ± 0.2
2AP	0.4 ± 0.3	0.7 ± 0.4	2.6 ± 0.9	3.3 ± 1.5	6.0 ± 2.5
DAP	0.4 ± 0.2	1.2 ± 1.0	2.2 ± 0.5	3.7 ± 1.9	5.7 ± 3.5
m6A	1.1 ± 0.4	1.5 ± 1.0	1.3 ± 0.3	1.5 ± 0.6	2.2 ± 1.3
Pur	1.2 ± 0.7	1.0 ± 0.2	1.2 ± 0.4	1.0 ± 0.2	1.3 ± 0.3
A70	0.6 ± 0.3	0.7 ± 0.2	1.0 ± 0.3	1.1 ± 0.2	1.1 ± 0.2
2AP	0.6 ± 0.3	0.7 ± 0.4	1.3 ± 0.5	1.6 ± 0.6	2.9 ± 1.4
DAP	1.0 ± 0.4	1.0 ± 0.3	2.3 ± 1.0	1.6 ± 1.2	2.2 ± 1.3
m6A	0.4 ± 0.3	0.7 ± 0.4	2.5 ± 0.7	3.8 ± 0.9	4.0 ± 2.6
Pur	0.6 ± 0.3	0.6 ± 0.2	1.9 ± 0.5	2.4 ± 1.0	5.5 ± 2.8
A77	1.0 ± 0.4	1.2 ± 0.4	1.0 ± 0.2	1.0 ± 0.3	1.2 ± 0.3
2AP	1.5 ± 1.0	2.0 ± 1.0	1.6 ± 0.5	1.5 ± 0.7	1.2 ± 0.3
DAP	0.8 ± 0.3	1.2 ± 0.5	1.4 ± 0.5	1.0 ± 0.3	1.4 ± 0.8
m6A	1.0 ± 0.4	0.9 ± 0.2	1.1 ± 0.2	1.4 ± 0.7	1.0 ± 0.4
Pur	1.3 ± 0.8	1.2 ± 0.7	1.0 ± 0.2	1.2 ± 0.6	1.2 ± 0.3

Experiments were performed in at least triplicate and, for some values, data sets were collected on both 5′- and 3′-labeled U1 snRNA to control for labeling effects. Errors represent the range of values seen in replicate experiments.