Table 1. Cleavage assays of P1.1 mutants.

Base pair	P1.1 identity 27-12/28-11	H-bonds	End-point (%)
0	UU/UU	0	<0.1
	CU/UU	0	<0.1
	GG/GG	0	<0.1
	UU/AG	0	<0.1
	UC/UU	0	<0.1
	GA/UC	0	<0.1
	UC/UC	0	<0.1
	GA/UU	0	<0.1
	UU/GG	0	<0.1
	CC/GG	0	<0.1
	AA/AA	0	<0.1
1	GU/UC	2	<0.1
	GU/UU	2	<0.1
	GU/AA	2	<0.1
	UG/UU	2	<0.1
	UG/UC	2	<0.1
	UU/GU	2	<0.1
	AU/GA	2	<0.1
	AU/CA	2	<0.1
	AU/AA	2	<0.1
	CU/AU	2	<0.1
	UU/AU	2	<0.1
	UU/UA	2	<0.1
	CU/UA	2	<0.1
	GC/CC	3	3.0
	CG/CC	3	2.5
	CC/GC	3	2.3
	CC/CG	3	3.2
2	UG/GU	4	<0.1
	GU/UG	4	<0.1
	GU/AU	4	1.2
	UA/GU	4	1.2
	UA/AU	4	1.3
	GU/GU	4	1.8
	GU/UA	4	1.8
	CG/UA	5	2.2
	GU/CG	5	4.1
	UA/GC	5	4.8
	CG/AU	5	12.3
	UA/CG	5	15.7
	GC/UA	5	29.1
	GC/AU	5	52.9
	AU/GC	5	58.7
	AU/CG	5	74.6
	CG/CG	6	4.5
	GC/CG	6	18.2
	CG/GC	6	33.9
a	GC/GC	6	89.6

^aIndicates wild-type sequence.